PMI: The Loan with an Increasing Interest Rate

Disclaimer

This is my opinion and not financial advice. Don’t use any of this information to make decisions.

Why post this?

This post is a little different than previous posts in the past, which have focused mainly on data science. I’m trying to get back into blogging a bit in 2024, and I wanted to write about something I don’t need data or really code for. We bought a house a few years ago and I thought PMI was interesting from a financial perspective and so wanted to share how I thought about it and why I tried to pay it off ASAP.

TL;DR

Separate your loan into 2 parts: amount required to remove PMI (PMI balance) and the rest. Looking at the interest + PMI as the total cost of the PMI balance shows that the effective APR for the PMI balance of the loan is much higher than your APR and you should pay it off over almost all other debts (even credit cards, but that may be a larger decision).

PMI: Mortgage Interest

What is PMI (Private Mortgage Insurance)? When you buy a house, if you don’t have a set % of the down payment (usually 20%), the bank will require you to have PMI, which is almost always a fixed cost amount that you will pay on top of any interest on the loan. You can have PMI for the life of the loan, but in many cases you carry (e.g. pay) PMI until you get to that fixed percentage, usually the loan is at 80% loan of the home value.

Note that the initial amount is 20% of the value of the home/loan (20% down payment), but you can remove it when you have 80% of the value of the home left on the loan (80% left). If housing prices stay relatively flat or moderately increase, 20% down payment or 80% left are the the same or very close. If housing prices increase dramatically, you can potentially get a reappraisal and your loan amount, which hasn’t changed, may be a smaller percentage of the home value. Some lenders do not allow you to remove PMI based on reappraisals, or limit the amount of time from purchase you can remove PMI for, such as within 3 years. This restriction won’t allow you to eject PMI if the housing market goes up dramatically, like in the past few years. Regardless, depending on your restrictions or how long you own your home, it’s important to know when you can get rid of your PMI so you know the target you’re aiming for.

Why is PMI bad?

PMI isn’t bad per se, as it is necessary to get the loan if you do not have a 20% down payment, which can be a lot of money. Also, even if you have 20% to put down, you may want that money in an emergency fund, need it for home improvements, or need that money to furnish your new home. The reason I’m writing about PMI is because when you consider it more of a removable fixed fee than part of a loan, which makes it somewhat unique in how the math works out on paying it off faster or slower. To demonstrate this, let’s look at how interest rates work on the loan and then show how PMI is very different.

Normal APR

For many loans, the relevant number is the annualized percentage rate or APR. In finance, building wealth in its simplest terms is taking all your assets (things that generate value or keep value) and your liabilities (things that cost value or depreciate) and trying to maximize the APR for the assets and minimize APR on the liabilities. This largely is due to the wonder of compound interest. Easily understood liabilities are loans, such as car loans, credit card debt, and student loans. Easily understood assets are brokerage/stock market accounts, savings accounts, and homes. We’re only going to talk about things in direct money amounts to simplify things, so we’re not going to go into house appreciation/depreciation and assume it is worth the same over time.

Your Home Loan

For simplicity sake, let’s say your home loan is $100,000 and you have to put $20,000 (20%) down to have a loan with PMI, but you are only going to put down 10% ($10,000). Let’s also assume your rate (APR) for your mortgage is 5%. Let’s say the PMI is $50/month, which is a small/moderate PMI in many cases. In some cases, PMI is > $100/month. Thus, we’re paying $600/year for PMI. We’re assuming a fixed rate loan (commonly 30 years), so the APR on the loan does not change.

We’re going to discuss mortgage payments without any other costs such as homeowners insurance or property taxes.

Amortization

Amortization is the gradually writing off the initial cost of an asset, or in this case, gradually paying down the whole mortgage. Let’s look at the amortization schedule for this 30-year loan without PMI, and then we can break down how much PMI costs as an APR. Any payment to principal with PMI is inherently going to the PMI part and not the rest.

To calculate the monthly payment, we’ll use the formula:

where i is our monthly interest rate: 0.4167% (5%/12 months), n is our total number of months (360 months for 30-year), and P is the principal amount. We will look at putting in 3 different amounts for principal: $80K (20% down), $90K (10% down), and $100K (0% down).

Here we can calculate the monthly cost (without PMI) for each scenario:

i = monthly_interest_rate = 0.05/12
p = c(80000, 90000, 100000)
# n = 1:(30*12)
n = 30*12
pmi_cutoff = 80000
get_monthly = function(p) {
  round(p * (i * (1+i)^n)/{(1+i)^n -1}, digits = 2)
}
a = get_monthly(p)
names(a) = sprintf("%4.0f", p)
a

 80000  90000 100000 
429.46 483.14 536.82 

Although we see that there is a $53.68 difference between the $80K and $90K bank notes, we haven’t taken into account the PMI. The reason I bring this up is that I heard “It’s only $50/month, that’s like 1 fewer dinner out a month”, which I think is technically correct, but not the way I’d see this in the lens of assets and liabilities. Even accounting for PMI, it’s about $100 difference in payments, but it may be clear when we separate the mortgage balances below how this thinking can lead to a very expensive liability.

Amortization/Paydown Schedule

Let’s create an amortization schedule. We will take the last months balance, multiply it by the interest rate to get the additional interest accrual, and deduct the monthly payment. Then we look at the the last 6 months of payment in years 2-3:

schedule = matrix(ncol = 3, nrow = n+1)
schedule[1,] = p
colnames(schedule) = paste0("base_", p/1000)
for (irow in 2:(n+1)) {
  schedule[irow,] = schedule[irow-1,] - a + 
    round(schedule[irow-1, ] * monthly_interest_rate, 2)
}
schedule = as.data.frame(schedule)
schedule = schedule %>% 
  mutate(month = 0:(nrow(schedule)-1)) %>% 
  select(month, everything())
gt::gt(schedule %>% filter(month > 30 & month <= 36))

month	base_80	base_90	base_100
31	76826.07	86429.45	96032.79
32	76716.72	86306.43	95896.11
33	76606.91	86182.90	95758.86
34	76496.65	86058.86	95621.04
35	76385.93	85934.30	95482.64
36	76274.74	85809.22	95343.66

After 3 years of payments, we can see how the balance difference of almost $10K or $20K remains even after 3 years of payments, for the $10K or $0 down payments, respectively.

Let’s wrap this into a simple function that takes in the principal, the monthly interest rate, the value at which the PMI is removed and the PMI cost per month:

make_schedule = function(p, 
                         monthly_interest_rate = 0.05/12,
                         pmi_cutoff = 80000, 
                         pmi_value = 50) {
  schedule = as.data.frame(matrix(ncol = 3, nrow = n+1))
  colnames(schedule) = c("balance", "payment", "interest")
  schedule$balance[1] = p
  a = get_monthly(p)
  schedule = schedule %>% 
    dplyr::mutate(payment = a,
                  interest = 0L)
  # fill in the amortization schedule
  for (irow in 2:(n+1)) {
    schedule$interest[irow-1] = round(schedule$balance[irow-1] * monthly_interest_rate, 2)
    schedule$balance[irow] = schedule$balance[irow-1] - 
      a +
      schedule$interest[irow-1]
  }
  # add columns for the month, principal paid, indicator of PMI and PMI cost
  schedule = schedule %>% 
    dplyr::mutate(
      month = 0:(dplyr::n()-1),
      principal = payment - interest
    )
  schedule = schedule %>% 
    dplyr::mutate(
      has_pmi = balance > pmi_cutoff,
      pmi = ifelse(has_pmi, pmi_value, 0),
      total_cost = interest + pmi,
      effective_interest_rate = total_cost / balance, n = 1L)
  # schedule$effective_interest_rate[1] = schedule$effective_interest_rate[2]
  # We can see the effective APR (PMI + interest)
  schedule = schedule %>% 
    dplyr::mutate(
      effective_apr = scales::percent(effective_interest_rate * 12, 
                                      accuracy = 0.01),
      effective_interest_rate = scales::percent(effective_interest_rate,
                                                accuracy = 0.001),
    )
  # remove the last which happens due to rounding
  schedule = schedule %>% 
    filter(balance > 0)
  schedule = tibble::as_tibble(schedule)
  schedule
}

To show how the PMI affects the interest rate of the total loan over time, we will use a 10% down ($10K), so the principal is $90K:

m = make_schedule(90000, monthly_interest_rate = monthly_interest_rate)
gt::gt(head(m))

balance	payment	interest	month	principal	has_pmi	pmi	total_cost	effective_interest_rate	n	effective_apr
90000.00	483.14	375.00	0	108.14	TRUE	50	425.00	0.472%	1	5.67%
89891.86	483.14	374.55	1	108.59	TRUE	50	424.55	0.472%	1	5.67%
89783.27	483.14	374.10	2	109.04	TRUE	50	424.10	0.472%	1	5.67%
89674.23	483.14	373.64	3	109.50	TRUE	50	423.64	0.472%	1	5.67%
89564.73	483.14	373.19	4	109.95	TRUE	50	423.19	0.472%	1	5.67%
89454.78	483.14	372.73	5	110.41	TRUE	50	422.73	0.473%	1	5.67%

Here we can see the effective APR over time:

m %>% 
  ggplot(aes(x = month, y = effective_apr)) + 
  geom_step() + 
  labs(x = "Month", y = "Effective APR (including PMI)")

We see that the APR levels out after the PMI is taken off and doesn’t really change much compared to the total balance of the loan, but does increase in the 3rd decimal of the percentage. This increase is small compared to the total balance of the loan, but I argue is incorrect to look at things this way. Regardless, an effective APR of 5% vs 5.75% but can still change decisions of where to allocate money: people may decide on paying the mortgage more compared to stocking away money in a savings account, bond, or other asset.

The issue with this thinking is that the PMI isn’t really on the whole loan, but only a portion of it, which dramatically changes how to think of it as a liability.

How to (correctly) think of PMI

The trick, at least for me, was to think of the whole mortgage broken up into 2 parts: the amount of the mortgage left that if I paid off it would remove PMI (PMI balance), and the rest of the mortgage (other balance/rest). In our example, the PMI balance would be $10,000 and the other balance would be $80,000. On the other balance of the mortgage, the APR on that $80K is 5%. On the PMI part, however, the APR is 5% + the rate induced by PMI.

When breaking the balances this way, which I believe is more accurate, we see the PMI balance as a considerably worse liability. This fact should not be surprising as the numerator of the APR (the total cost) has a fixed amount/fee (the PMI), but the denominator (PMI balance) shrinks each month.

Let’s look at the first few months and the effective APR on the PMI balance:

m = m %>% 
  mutate(pmi_balance = balance - pmi_cutoff,
         pmi_balance = ifelse(pmi_balance < 0, 0, pmi_balance),
         other_balance = balance - pmi_balance)
m = m %>% 
  mutate(pmi_balance_interest = round(pmi_balance / balance * interest,2),
         other_balance_interest = interest - pmi_balance_interest)
m = m %>% 
  mutate(
    pmi_balance_total_cost = pmi_balance_interest + pmi,
    effective_pmi_balance_apr = pmi_balance_total_cost/pmi_balance * 12,
    effective_other_apr = other_balance_interest/other_balance * 12,
    effective_pmi_balance_apr = scales::percent(effective_pmi_balance_apr),
    effective_other_apr = scales::percent(effective_other_apr))
data = m %>% 
  filter(has_pmi) %>% 
  select(balance, month, pmi_balance,
         effective_pmi_balance_apr, pmi_balance_interest, 
         pmi_balance_total_cost, effective_apr)
gt::gt(head(data))

balance	month	pmi_balance	effective_pmi_balance_apr	pmi_balance_interest	pmi_balance_total_cost	effective_apr
90000.00	0	10000.00	11.000%	41.67	91.67	5.67%
89891.86	1	9891.86	11.066%	41.22	91.22	5.67%
89783.27	2	9783.27	11.132%	40.76	90.76	5.67%
89674.23	3	9674.23	11.202%	40.31	90.31	5.67%
89564.73	4	9564.73	11.273%	39.85	89.85	5.67%
89454.78	5	9454.78	11.347%	39.40	89.40	5.67%

We see on that $10K the APR is effectively over 11%! Now, even with a great APR (such as 3%), with PMI, the rate is likely high enough that if you have the cash to remove it, it’s a better to remove the liability than to keep the $10K asset, unless you can beat 11% (and tell me how).

Looking after 3 years of payments can give you a better idea of the effective APR on the remaining PMI balance (spoiler, it’s > 15%!):

We can see this effective APR for the PMI balance during the first 6 years:

data %>% 
  filter(month <= 72) %>% 
  mutate(effective_pmi_balance_apr = 
           as.numeric(sub("%", "", effective_pmi_balance_apr))/100) %>% 
  ggplot(aes(x = month, y = effective_pmi_balance_apr)) + 
  scale_y_continuous(label =  scales::percent) +
  geom_step() + 
  labs(x = "Month", y = "PMI Balance Effective APR")

This APR increase isn’t shocking if you think of the majority of the numerator getting larger in light of compounding interest being reduced by payment of the balance, but still shocking when your APR goes like that.

And, most drastically, let’s look at towards the remaining balance after we’ve made almost all of payments:

The effective APR is > 100%. I don’t care what asset you have, you’re never going to beat that. In many cases, when looking at the small balance needed to remove PMI, it’s a clear cut case to pay additional money to remove it, but it’s hard to see that affect as strongly towards the beginning of the loan.

Conclusion

Obviously, if you have enough money to get a mortgage without PMI, then do it. Many can’t, hence why they have PMI in the first place. I think the message of “have more money” is silly and unhelpful.

I think the interesting part of this is seeing the balance left to remove PMI and the additional remaining balance of the mortgage as 2 separate loans. Mentally and practically, I think it makes it clear that PMI is a really bad liability. Most surprisingly, it can be even a higher effective APR compared to credit cards! The big difference compared to credit cards and other APR-based products, however, is that PMI is not interest and does not compound per month. But that same fact that PMI is fixed makes for an interesting interest vehicle and warrants a closer inspection other than “it’s just another $50/month”. Though true, when looking at it through the lens of asset and liability interest rates, it should have a high priority for removal in your debt profile and increased priority over time, especially after you have saved up after the initial home purchase.

Some things I wish I knew about Grad School

I'd like to thank Elizabeth Sweeney for some pointers on this post. All the thoughts are my own, so don't blame her for anything below.

A little about me

I am from a middle-class family from Southeast PA. We never had any serious money issues when I grew up that I remember, but I would not say we were flush. I did go to a Catholic grades school until 6th grade, then I went to public school. I had an IEP (Individualized Education Program) and was involved in “gifted” classes. My high school was a good school with a number of advanced placement (AP) credits. We had guidance counselors and administrators that knew your name.

Both of my parents held full-time jobs my entire life and are tremendously hard working. Neither graduated from college, but my mother did work in admissions at a University, so she had a wealth of knowledge to navigate applying for school, finding scholarships, and also had the benefit of tuition benefits from her job for her institution and a number of reciprocating institutions.

The reason I bring this up is a number of reasons: I was gifted academically, so graduate school was a drastic change and much harder than any education I had previously, I had support throughout my career that not everyone have, and I had someone with know-how of applying for undergraduate and graduate school. So while I'm a first generation college graduate, I had a leg-up on many others like me.

I'm talking about my one, singular graduate school experience. I'm also a white, cis-gender male with a generic first name. There are a number of hurdles I've never encountered. I focus a lot on money and resources throughout this post, but there are a number things I haven't even considered. Please feel free to tell me some things you wish you knew about grad school on Twitter \@StrictlyStat.

The goal

The goal of this is to discuss some of the things that I wish I knew about graduate school, especially the application process and the first year. I only went to one place for grad school, both my Master's and PhD, so these points may not be generalizable to all graduate schools. Also, Johns Hopkins was a tremendously supportive institution with respect to money and people's time in grad school. Blind spots still exist for all institutions. I hope to add comments on what institutions could make this easier or information on how students can help themselves (as many may not point this out at the time).

Many of these blind spots are not intentional, but due to not thinking about it (see Hanlon's razor). You'll realize that when you ask questions (which I promote throughout) and will hear a lot of “Oh, I've never thought of that. No one's ever asked that before, let me check” responses.

What is graduate school?

Graduate school is a time to learn independent research and learning. You are a student, but really a partner in your own learning. Strike that, you own your own learning. Taking ownership over your own learning is a key difference from graduate school compared to all other education before it (at least in the US). In many cases, the classes and structure are to give you a foundation and teaching you how to learn. In essence, your program will give you the tools to teach yourself, not teach you everything you need to know. Also, many sets of required courses are not even the bare minimum – many programs expect you take electives to specialize in your field. So while some classes “didn't teach me all I needed for this topic”, understand that it's partly on you to fill in the gaps. Now, if you believe egregious errors or sets of materials were omitted from a course, you may want to speak to the graduate program director or the chair or send an anonymous email.

Network

It's OK not to have an extensive network of connections starting out. Talking to your undergraduate advisor or another faculty member and leaning on their network is a great strategy. If you don't have those, reach out to faculty/students at other institutions. Most people are happy to spare some time or impart some wisdom (or at least assumed wisdom).

Reaching out to Faculty/Students

Before you apply or enroll somewhere, you should feel free to reach out to current faculty and students. Note, many faculty get a lot of requests like this. Be explicit and as clear as possible. I might say something like:

Dear Dr. XXX,

My name is John Muschelli – I am a prospective student for your department. Would it be possible to have a 30 minute call to discuss your research? I would like to know if YOUR DEPARTMENT is a good fit. I'm happy to converse via email if you do not have time.

Specifically, I'd like to know about YYY research and what students you advise?

Thank you,

John Muschelli
Phone: 555-800-8000

where you can leave off the “Specifically” line. This indicates that you don't want anything other than information, as opposed to a job, a position in the lab, a recommendation, etc. This leaves the door open for them to not respond (which you should consider when applying), or a short call where you have a prepared list of questions (that you should send them), or an email exchange. Don't spam the whole faculty – we talk and will ask “Did you get an email from so-and-so?” which will reduce the chance of discussion. I'll talk more about conferences, but it's also a great idea to do this if you are going to a conference and search the program for people from an institution you are considering. Don't overdo it though – these people will be at other conferences in the future and you don't want to be pushy.

Social Media

It's a digital age. Your social media can be used immensely for networking in a professional setting. If so, make sure it's professional. Use privacy settings in all applications. Reaching out to faculty/students on some platforms can provide a better interaction than email. It can be hit or miss with people, but another avenue. Also, make a website and probably a GitHub account. People will Google your name and you control what's on your site. Use the blogdown blogdown package, and buy a domain on Google (https://domains.google/) for $12/year (year 2020).

Get to know your classmates

Your classmates are your future network. Get to know them better than mere acquaintances. Some will become friends, but almost all will be come future colleagues, collaborators, or contacts. If you go into academia, these contacts will be at places to send your students, either for faculty positions, internships, or jobs. My message (one from a friend) is this: Be generous and share with your classmates to at least get as many perspectives as possible and don't be an island – do group study sessions. You can't always be the best in every subject, work with others. Graduate school is a time for independent research, but not alone research. Ask anyone, and they will tell you that no one works completely alone (at least in Biostatistics).

Money

The #1 thing I'd say I did not understand starting grad school was Money. And as the great Wu-Tang Clan said: C.R.E.A.M..

I didn't know what my value was with respect to getting paid. I didn't understand how to identify payroll issues. I didn't understand taxes. I also didn't know how to handle money, but that was a moot point because my budget was exactly “I need X dollars to live and let's get X+c dollars”, where c was some number where I could eat out a few times a month if I wanted to, while taking out loans for my Master's. Probably most importantly, I didn't understand professional expenses.

Applying to a program – look into a waiver

But before we get to expenses while in the program, let's start with first things first: applying to programs cost money. This cost includes the application fee, taking the GRE, maybe some GRE prep book, and maybe taking the exams multiple times. For the application fee, look on the website and see if there are any waivers. The waiver will likely be school-wide, less likely department-specific. If you can't find the waivers, ask the graduate program director (Google them), a departmental administrator, or the registrar. Also, ask the program director if you not qualify, but believe you still should be eligible for one. Even low-cost application fees add up over applying to a number of schools.

How to make this easier – put on every application page where to apply for a waiver (don't bury it), including department website areas for prospective students, including explicit information about the process.

For example, simply adding:

Please apply for our program by December 1, 11:59PM. Here is the link to the application and a link to the application fee waiver. If you don't qualify, but have need that is not forseen in the application fee waiver, please contact this.person@institution.edu.

You visiting a program – paid or not

You got a visit to a program, great! You should ask the graduate program director if travel and lodging is included. I have found that this commonly happens in PhD programs in Biostatistics/Statistics, but not really Master's programs. Many departments will book travel for you. Understand that a department should have funding for this, as recruitment is an essential function of a department, and without providing these costs will likely gate-keep for many lower income applicants or those without disposable income from their support. If they do not provide funding and you cannot pay for the visit, request an online visit.

Again, ask questions. Ask if this is provided if not clear on their website. Ask if you stay an extra day to see the city, is that on you or the department.

How to make this easier – For example, simply adding the following could clarify many questions before an email is ever drafted:

By Mid-January, you will get an email from us. That is sometimes February. If you don't hear back from February 1, please email this.person@institution.edu. There will be a few phone calls with faculty. We will then get back to you if you are being asked to visit by February 9. If you are asked to visit, we will pay for lodging and travel, scheduled for March 1. You will spend 1.5 days on campus, visiting faculty and students, seeing the campus, and then will have breakfast/brunch the next day followed by a tour of SOME AREA.

Many times these things exist, but behind some firewall, intranet, or are not indexed by search engines. I'm unsure if there are policy issues why sharing this would be an issue, but I think this is helpful for most students.

Professional Expenses

The example of travel/lodging being paid by the institution was something I would have never considered before. I'm not indicating academia is a “business” in the same sense as other corporations, but it is a profession, and therefore has professional expenses. Many departments have recruitment budgets, either for recruitment of faculty or students. Also, many times in your career in graduate school you'll need something for your research to go forward.

Things like, books for class, computers, computing costs, printing costs (it's real), software costs (Adobe Acrobat anyone?), etc. Some of these costs should be explicitly discussed with you. Others may be discussed only after you accept the program, but you can always ask about them.

Probably the most important message for this whole post is:

Asking for things is not only OK, but is expected

This message is for anyone in academia, including faculty. A colleague of mine encapsulated it well: ask yourself “Am I supposed to pay for this or should this be paid for by someone else”, where that someone else may be an advisor, a grant, the department, or the school. You'll never know without asking.

One of the first expenses is usually a new computer (if necessary) and books. Ask more senior students or faculty to borrow their books. You'll eventually want to buy the standard reference texts, but many books can be borrowed. For biostatistics, we are on our computers a lot of the day, and our program provided funds for a computer and books the first year. These funds were essential for first year success.

One of the most expensive costs are travel, usually for a conference. Ask if your institution pays for a conference a year, and if that includes travel and/or lodging. Does the institution book this for your or do you do it on your own? This distinction is crucial: if the institution has you book the travel and reimburses it, what is the timeline for reimbursement? You will have to float that money (interest free) until you're reimbursed, which can take a long time in some places. I didn't have a credit card coming into graduate school and realized that I needed one because I couldn't loan out these amounts out of pocket. See Get a Credit Card below for more discussion.

Similarly, does the school reimburse conference registration, which can be > $500, even for students, only after the conference has been attended? Again, ask your advisor/graduate program director what funds are available for this. Many student paper awards exist, but may not cover everything – who (if anyone) can fill the gap in costs? Also, does the institution have a per diem pay for food (which is destination-dependent) or do you submit receipts? Again, this fact can change how you do meals with colleagues from other institutions.

Although I recommend to apply to departments/work with advisors where the research interests are aligned and personality allows for good collaboration, asking about what percentage of your students in your department/lab go to 1 conference a year? What percentage go to more than 1 conference throughout their graduate school? Conferences are a huge networking tool depending on your career trajectory; you should know if departments value and support them for students (or if they do not).

How to make this easier – discuss these issues with visiting students and put a simple document (behind a firewall/intranet) for students as a reference:

Here are student award options: link, link, link, etc.

Students get $XXX first year for books/computers. You can/cannot buy tablets with this. If this is not sued by year one that does/does not roll over.

When buying supplies for research, make sure you talk to XXX to be able to use the institutions tax-exemption. We cannot reimburse tax.

Conferences are typically paid out for students by advisors. Please ask your advisor their policy.

Reimbursements can take multiple weeks to be paid out. There is a department card you can use, please ask XX before applying

or

Reimbursements can take multiple weeks to be paid out. Costs of travel and registration can be burdensome, please determine if a credit card.

The last one get sticky because credit card debt can be devastating if it gets out of control.

Get a credit card

I recommend getting a credit card for professional expenses. The reason is that many times you'll have known costs for the future, they will be outside of your budget, and you'll get reimbursed. That mix makes it possible to apply for many fee-free credit cards with sign up bonuses. These bonuses get applied when you pay a certain amount ($1000-$3000) in a certain time, such as 3 months. With conferences and travel (if you're booking), you'll almost surely pass that milestone, especially if you use it for other costs.

If you do not use credit cards or do not think you will use them wisely, I'd recommend only using it for travel. Credit card debt can cause financial issues long-term and I don't want to say that they are universal for people. I would only recommend a credit card if you know you can pay it off in full by the end of the month. Thus, asking the time for a reimbursement to go through should be known beforehand. Also, timing when you make the purchase, such as right after the last credit card statement, can maximize your time to get reimbursed.

The perk is that you don't need to float hundreds of dollars for months in advance (conference registration is well in advance). If you cannot withstand this financial strain, talk to someone. I had situations where I said to an advisor or administrator “I don't have the money to front that” and I was accommodated. If accommodations are not available, and you do not want to borrow money (you should not have to), then I personally would withdraw my registration and submission. This scenario is probably the worst case, but if this ever happens, you should reach out to graduate program directors and the chair because small (relative to the department) financial issues are hurting the research and science, which people take very seriously.

There are a number of sites out there that tell you about what credit card is best for you, but I personally like NerdWallet. Again, make sure there's no annual fee for your first card as you're trying to save money here!

Moving Expenses

I haven't heard any graduate students getting moving costs covered by a department, but those costs can be significant. I would highly recommend discussing this with the program director if you will be struggling to get to the new city/place. I echo this especially for post-docs: ask your advisor. Negotiation is usually possible.
These expenses are also relevant for new faculty (who may be a newly-minted PhD or post-doc). I posted a tweet about this and you can see what the responses were for reference. In many industry positions, moving costs are covered or are bundled into your signing bonus.

How to make this easier – I don't know how to rectify this blind spot without setting out departmental funds. If you're a joining faculty, negotiate it in your offer.

Dinners with Faculty

Many times you will go out to dinner with faculty, usually with seminar speakers. These dinners should be provided by the department. These are amazing networking opportunities, especially when you're applying for a job on the market, and a way to explore the food scene in your area. I didn't know this, and I remember feeling uncomfortable going to my first seminar dinner because it was expensive and I got a small plate for dinner and said I wasn't hungry. I was relieved to see a faculty pick up the tab, and didn't know until later that students were not expected to pay. There will be situations where faculty ask you out to dinner and usually etiquette will dictate they pay, notably if they choose a place out of your price range. If they don't, my vote is to swallow that bill and then politely decline future invitations.

How to make this easier – Make a one-page document that discusses faculty/professional dinners for students. Is alcohol included (maybe reinforce codes of conduct)? How is transportation organized (usually day of and you may be on your own)? Who typically pays (usually the host)?

Mental Health

Mental health is a huge issue in graduate school. A lot of people in graduate school struggle with mental health issues, some caused by graduate school and transition, and many issues are exacerbated by the stress in grad school. The truth is is that graduate school is hard. It's hard because research and trying to push on the limits of a field is hard. Stress, unfortunately is usually a byproduct of this. I'm not trying to be insensitive and I'm not saying that stress can't be lessened or reduced, but I do not believe a stress-free graduate school experience is possible. A low-stress one is maybe possible, but rare. I do believe however, that increased organization and structure could mitigate this stress.

Stress can come from a number of places. As someone who came straight from undergrad, the biggest changes for me that caused some stress were that 1) you will feel like an imposter, 2) you don't have a “boss”, and 3) there is not right answer. Now, I had a great grad school experience and never had to deal with harassment or abuse. These issues are serious and should be brought up to a faculty administrator immediately. Institutions take these issues very seriously and provide health (mental health is health) services to students. So please use any resources at your disposal.

You are (not) an imposter

I wrote a full post about imposter syndrome at https://hopstat.wordpress.com/2015/10/14/dealing-with-imposter-syndrome-in-graduate-school/, so this will be brief. Essentially, my argument is that you are likely comparing yourselves to your more-advanced peers or, even worse, faculty based on skill and accomplishments. This comparison will make you feel inadequate. Also, let me say this again, graduate school is hard. I felt I was academically-inclined for most of my career and being the one that “didn't get it” was a change. I believe experiencing that drastic change helps people becoming better educators by having more empathy and being able to put themselves in students' shoes. I had to learn how to ask about 1000 more questions than I was used to. It took a lot of confidence reinforcement for me, but I came to the conclusion that I hated not knowing what I was doing than any embarrassment by feeling like I was asking obvious questions. One of my life mottoes is “Never feel too stupid to ask a dumb question”.

I ask obvious questions all the time. It's to make sure me and the person presenting (or getting presented to) are on the same first page. If we're not, then there's no point in discussing things more. Also, as someone who teaches, many instructors yearn for engagement. Ask questions.

You don't have a boss

When I say “you don't have a boss” I mean it 2 ways: you don't have a “boss” and you don't have A boss. The first way indicates to me that you will not (usually) have someone asking where you are from 9-5 and checking your office. You may have to log hours, but maybe not. Some weeks you'll get a lot of work done, beating down your inner imposter. Now many advisors do regular check-ins, lab meetings, or are in the same physical space as you (as in a lab). But most times everyone is concerned with their own work and research. This lack of checking in is many times intentional – again, graduate school is a time to learn independent research. At this point in your life, you're an adult and will likely be treated accordingly or as an employee. The flip side of this is that you have immense control over your schedule and flexibility. This flexibility can be a curse if you're disorganized (such as me) or sometimes struggle with discipline in work (also sometimes me). I'm still learning that motivation is fleeting, organization wins championships.

Now, as you don't have one person checking in your work, but you may have several people checking in, or who are your “boss”. For example, you have an advisor, but also a chair. You may be a teaching assistant. Your teachers assign “work”. The graduate program director also oversees your overall progress. You have an advisor you work with, but maybe a number of collaborators with different projects, all asking for their results. Thus, again, graduate school is a time to learn what organizational schemes work for you and what you can do independently. I will say that there isn't any hand-holding here in many cases. I remember the first report I made for a collaborator, that was asked for on short notice, and I got it back with the words on the top “This is shit”. And it was. It was not personal. I am a negative-reinforcement learner and I took that criticism to make a better report. I also essentially said: “I agree it's shit, but you wanted it in a day, so you should probably expect shit”.

Efficient communication and asking a lot of questions is one of the things I have found to help. For example, asking “What would you prioritize over X and Y” or emailing “I have another project that is my top priority due to a deadline, could I get you X by Y date?” can go miles. Communication is only half the battle though, sometimes both people say “yes I want it now”. You either need to clear some weekend or night plans and plow through things (WHILE STILL SLEEPING) or you need to have your advisor do some time-protection work if possible. Also, I have found that people can easily say “yes I need that NOW” via email but those things change during a phone, Zoom, or face-to-face discussion of your priorities (including other priorities of their projects). Also, understand that schools of public health, nursing, medicine, and arts and sciences have very different cultures. When you cross these areas, norms and acceptable things change and you should be aware.

Work Schedule

The role of statistics and biostatistics is to quantify uncertainty, learning to live with uncertain answers is part of the learning. One big issue is that research is never “done” and there is no “right” answer. No one is going to tell you that you were 100% right. That's science. Thus, you can work until you get things done to your satisfaction. That can push projects forward, but also keep you up late into the night or laying awake in bed thinking more could be done.

So although you can usually make your own hours – give yourself a structure. Getting into a solid rhythm is helpful and can provide a solid foundation, especially when times are hard. Coming in by a certain time, leaving by a certain time, working a set number of hours, or setting a number of tasks for the day and then leaving when done are all good strategies for a work-life balance. During courses this will be hard. During independent research, this structure can make things easier immensely.

Lastly, the structure will allow you to finish the last 10-20%. When you get a new project, it's exciting and everything you find may be interesting. When you've reread the manuscript you're submitting for the 20th time and getting another round of edits, that project may physically disgust you. You're over it. You're not motivated to work on it. Without pushing from others, the structure gets you over the line, sometimes like a marathon runner, exhausted, sore, and sweaty.

Random

Dress code

I came to grad school wearing hats every day, sandals, plaid shorts, and t-shirts to class and meet with faculty. While my dress has slowly navigated back towards that, luckily ditching the plaid shorts, that's likely because I'm a faculty member and have a bit of freedom over my dress. I remember taking classes with medical students, who dress in professional garb, including ties, for the first few weeks and feeling immensely under-dressed the first class or two. I'd recommend dressing semi-professional, ties are not necessary, but shoes, pants, dress/skirt, or something of the like would probably be a good first try at first days of class or meetings with faculty. You will get the hang of what you can wear that fits with your style over time, but probably go more professional to start. Also, dress professionally when meeting individually with the chair, dean, or any administrator you don't know personally. But maybe things have changed, that was like > 10 years ago?

Graduation

You need a cap and gown (regalia), just like in undergraduate ceremonies. One key difference is that if you're getting a PhD and going into academia, you may need that regalia for future ceremonies with your students. These are not particularly cheap (https://academicregalia.herffjones.com/category/detail/categoryID/3291), and can be upwards of $1000. I recommend buy them after you are in your position for some time and likely more financially stable. And if you don't go into academia, you won't have that gown just staring at you in your closet, just asking how it's going to turn into on expensive Halloween costume.

The 3 ‘Times’ of a Project

During a conversation with Sean Kross about projects, particularly data science projects, I tried to explain how things can go right and wrong with a project. I was explaining things with respect to being the data scientist on academic projects, but I think these issues are cross-cutting so figured I’d post them here.

I thought back to when projects did not go well or someone was left frustrated or angry during or at the end of the interaction. To me, the issues usually come down to the 3 “time”s of a project: time, timeline, and timeliness.

Before talking about these “time”s, I think it’s important to note that most of the frustration really comes down to miscommunication. The miscommunication or differing expectations, in my opinion usually fits into one of these time buckets.

Time

Time represents how long you estimate to do something. Particularly, this relates to how many hours a week you can work on a project, or percent effort, also called %FTE (percent full time equivalent). “Time” also means there should be a discussion of whether you have the space in your schedule to commit to something. Many instances you may not have space but you’ve been “strongly urged” to do the work.

Helpful things to do:

1. Do not say how many hours you have available. Tell them 80% of that or tell them how many you want to work on this. Time is a fluid – it fills the space provided.
2. Sometimes work out 1-2 “hypotheticals”, such as what if the data is in terrible shape. Even better, wait to give a yes or a no for accepting a project until after you get some of the data, but most people assume you are a “yes” once you get the data.
3. Estimate (or overestimate) how long the first set of tasks will take.
   • this sets the precedent for the project.

It’s fine to deliver this a bit quicker than projected. It excites people (“That was fast!!”), but you can still lag on sending it exactly when it’s done. This time slack allows you to think if the results are right, but more importantly makes it so that when things go wrong (WTH is that data point!?) the expectation of a quick turnaround is mitigated ab it.

One of the main issues is that novelty is a cruel mistress. New and shiny things are exciting. Most projects sound like they can change the world or practice or our understanding of an area. Some can, not all do. Think of a project you’re on right now and try to answer the question that if it dropped right now and someone came back in a week and asked what time you could dedicate to that project again. Would it be the same? How much less? Think of your good and not-so-good projects, and averaging that might give you an idea on how you’ll feel about this new project in 3 months.

Timeline

I know you’re saying “3 months from now!? I get all my projects done quickly!”. That brings us to timeline. The full timeline of the project is the how long the overall goal or set of goals for a project is going to take. This discussion usually is more overarching than the time discussion for a specific task. Is the project one paper? Developing an entire suite of work? Multiple clinical trials?

But let’s focus on one analysis, that (hopefully) results in a paper.

A few questions that could be helpful are:

1. When do you plan on submiting the paper?
2. Are all the patients/subjects enrolled followed up?
3. Is someone (student/intern/visitor) leaving soon and this needs to be done by then?

Many times you’re not privvy to the internal workings of a group, including the fact that the data they’re about to give you may have be stopped and started 3 different time with different analyses.

Many people think once the paper gets thrown down the ravine to the wolves of review, it’s out of sight and mind and never thought of again. But then, it crawls up, bloodied and beaten, back from the land of reviews into you line of sight: REVISION!

You need to ask: When will reviews likely get back from this journal, what’s the turnaround time on those usually (2 weeks to 1 month), who will take lead?

Other important timeline questions:

1. What other projects will start once project 1 is done?
2. What if I need to move my time around after this project is done, who can take over?
3. What if things significantly change? Examples: you’re grant gets funded! Your main collaborator’s big grant gets funded! You are planning in changing jobs?

Timeliness

Although it may be a bit of an abuse of the term, the last time is timeliness. I consider timeliness similar to responsiveness. Many projects have long or short-term explicit goals, like a paper or book, but many have implicit deliverables along the way, like short presentations. The discussion here is something like “If you send me a question about this project, how fast do you expect me to respond? Same hour? Same day?”. This discussion sets up the ability to use keywords such as URGENT or NON-URGENT. These can be abused, but at least you know what one party believes is important so that they don’t come back later and indicate you shrugged off something for another day that was pertinent.
Also, effective email writing techniques such as putting in an estimate of how long you think a task would take (could be way off – again good to know what people think) or putting a TL;DR (too long; didn’t read) synopsis at the beginning of a long-worded email.

We’re all battling the evil dragon of email back daily, trying to rescue the prize of “free time”. These little things allow people to prioritize tasks for a project and not open a 2-page email, be overwhelmed and close it, putting it off until later. A little TL;DR can make things a tad easier. Remember that people use email in very different ways; that long email may be a stream of consciousness mess or a well-itemized TODO list that people should refer back to. Now many, and I mean many, different project management solutions exist for this type of work, but 1) I can’t find anyone who agrees on which one to use, 2) some are unwilling to pay for these solutions, and 3) if you’re a data scientist you’re usually not able to force the use of these. Even if you can force using this solution, the next project may say no.

Although most don’t use “project management” tools per se, there are services that most are amenable to that can help these issues. For example, shared folders such as DropBox, OneDrive, and Box provide a one stop shop where materials should be created. Writing a paper? Use Google Docs, or for the LaTeX crowd, Overleaf. As an aside, Overleaf is a great product, that you can even use knitr in! Once they make a way to use this with Rmarkdown (I’m looking at you RStudio), I will throw down the gauntlet and try to only use this service, as it incorporates LaTeX/PDF, dynamic documents, can output DOCX, PPTX, slide decks. ANNND Back to other tools like GitHub for a shared space for code. At the end of the day, you’re trying to end the torment of an email with an attachment of Manuscript_FINAL_2020May15_JM3_REALFINAL_willThisEverEnd?.docx. Many of these tools are painless replacements for the email song and dance, have version history and track changes. Push or them.

I have had horror stories of timeliness. I have had emails that said WE NEED THIS RIGHT NOW. Long into the night, breaking my back (but probably neck because ergonomics is hard) for this project, I’d send off my finished product. Then I’d wait. And wait. And forget. Then remember and get mad that I hadn’t heard anything. Then ping the email and get nothing. Then I’d look up, 6 months had gone by, and I had realized my beard looked like Tom Hanks in Castaway, and feel the serene closure of letting a dead project die. Then a week later I’d get an email saying Thanks for that! WE NEED THIS OTHER THING RIGHT NOW. Don’t do this for your mental health, the health of your facial hair (or lack thereof), and for the stress balls that may explode otherwise.

Conclusion

Time is a fickle thing that we think we have none of (today), a world of (I’LL NEVER DIE!), or some (let’s have a quick chat). For projects, time discussions and expectations are vital to a good collaboration. Like an awkward first date, sometimes you need to get some of the cards on the table otherwise you end up down the line as a depressed John Cusack as he has played in so many movies. Talk about your 3 times of a project, be happy, and collaborations will hopefully flourish!

Some Thoughts as a Junior Faculty (at JHSPH)

Being a Junior Faculty member, or considering it, leads to a lot of questions. I hope to answer a few of them here. Some of my statements will be specific to Johns Hopkins Bloomberg School of Public Health (JHSPH) and maybe specific to the Department of Biostatistics. Disclaimer: this is the only department I have been in (for PhD and faculty), so not all of these may generalize or apply. All of these opinions are my own and all of this is knowledge that was not taken in confidence.

Do you want to be a faculty?

First and foremost: do you want to do this? I'm not saying you need to be 100% sure about everything and this has been your lifelong dream and you've never thought about anything else. I'm saying, did you like writing papers and doing research, where much of the work you needed to be independently motivated? I like going down the rabbit hole and finding out where it leads me. Maybe too much at times. That means finding a bug in my code, figuring out if my hypothesis is off the mark, or whether I can tackle this problem in front of me. The independence is a large draw for me.

Overall, I believe the flexibility/independence to work on what you're passionate about is the main draw of academia. That doesn't mean you'll never have to do things you don't like or aren't passionate about. It means that you'll have the opportunity to explore your own ideas if you want, or work on interesting research that just-so-happens someone else wrote the grant for. A lot of the other perks of academia you can find in other industries. Many jobs today are allowing for flexible time schedules, conference travel, up to 20% independent research time, remote work, and other things that were unheard of 25 years ago. That's not a bad thing for academia, but just that those perks are not only for academic faculty.

That independence/flexibility comes at some cost. For one thing, you may be paid below “market rate” in industry or consulting. The main cost I see, though, is that independence can be hard sometimes, at least for me. I don't like being told what to work on all the time (see rabbit hole above), but I do like some structured work that has deliverables. Trying to reorder your priorities fluidly can be a bit draining.

One of the best analogies I've heard about being a junior faculty is that your own startup. You're the CEO of your own career. You're finding funding usually by grants compared to VCs. You're a recruiter, usually of students and other collaborators. You're your own assistant, scheduling meetings, staying on top of your email, booking your own travel (maybe), and running the meetings. And you're the team doing the research, writing the code, and delivering the product (papers/presentations/grants); you're the advertiser of the product (vlogs/blogs/presentations/papers/classes). Over time, these roles change in the percent of time you spend doing each task, but when you start out, you're it. And lastly, you're setting the agenda and vision for your career.

I'm an impostor: I don't have ideas

Many graduating students have the concern that they will not have enough ideas to generate new papers or grants. I'd stay that's generally not something you should worry about. No area of research is completely explored; but it may be an issue if you are too narrow in your scope. Almost every paper I have finished has led to at least 3 more questions. Those questions may be about that data set or method or about new data we need collected. Even if your well of ideas dries up temporarily (highly doubtful), if you have energetic collaborators/mentors, they will have enough ideas to lend you. If you're working on something someone else suggested, I recommend to 1) understand why it's important before starting, 2) making sure you have enough interest/passion in this topic, for those nights where the project has turned to your worst enemy, this passion keeps you from totally throwing it in the garbage, and 3) to have expectations discussed before doing the work with respect to the level of help those suggesting is providing, and 4) make sure authorship is at least discussed a bit before doing a whole bunch of work. If that doesn't work, go to one conference and see if you don't come back with a handful of ideas.

Soft money vs. Hard money

Soft-money generally refers to salary funding coming from grants or other awards rather than tuition or endowments. Hard money is the opposite and many times the majority of your salary will come from teaching. There are numbers such as “2-1”, “2-2”, “1-1” that refer to the number of classes you teach in a semester for hard money positions. JHSPH is generally a soft money environment. Moreover, we are in a quarter (not semester) system, so the numbers do not mean the same thing. Depending on how much you teach, however, you will be required to cover anywhere from 60-85% of your salary as a tenure-track faculty at a given time on grants or awards. If you're research track, make it 75-100%.

Research Track vs. Tenure-Track

First off, I'm an Assistant Scientist at JHSPH. This means I'm a research-track faculty member. Other institutions have different names for this track and also may have different tracks for research or clinical work, etc. In some departments, research-track faculty members are treated starkly different than tenure-track members, not just implicitly: some have different voting rights and restrictions on their work and/or mentorship. In Biostatistics at JHSPH, research/scientist- track members have similar voting rights (not completely the same) and are treated very similar to tenure-track faculty.
For example:
You can teach courses.
You can have discretionary accounts.
You can be the PI on a grant (or co-PI).
You usually get competitive offers and can use the AMStat news to guide your salary.
Skills related to research, teaching, service, and mentorship are extremely useful.

Some differences worth noting are:
You cannot be the primary research advisor to a PhD student. You can be an advisor, not the primary. You can be a primary research advisor for a Master's student.
This has pros and cons. You can't be the primary mentor, but can still work with students, and tend to not have to find funding for them as that is likely the duty of the primary advisor
You don't have a built-in sabbatical whereas it's more assumed for tenure track. You could potentially negotiate this.
You are usually hired under a project or a direct mentor.
This does not imply that you cannot work on your own work, but that initially you don't have to find all of your funding when starting.
The search, hiring process, and requirements from the dean is not exactly the same as tenure-track
Startup packages are not necessarily the same. Again, could potentially be negotiated.
You start working on day 1, compared to some “protected time” with tenure-track faculty.
You don't have a “tenure clock”. This can be a double-edged sword.
On one hand, you don't have the same timeline pressure.
On the other hand, you may need to make a concerted effort to set up meetings with your chair and/or mentor to discuss progress with respect to promotions. Our chair has yearly progress meetings with all faculty, regardless of track.
This can also lead to more variable promotion timelines. This can be mitigated by clear communication from the chair and mentor about expectations and previous precedence.
You have different expectations for promotion. These can vary wildly from institution to institution. We have similar expectations in many respects at JHSPH, but do not have as many external letters required for the promotion committee.

Mentorship

How do you choose a mentor? Well, find someone you can talk with, that knows stuff about stuff you don't know well, and will agree to make time for you. We have one formal mentor. But most likely, you'll have many mentors. One is likely to be in the department, but you'll likely find mentors that are collaborators. There are some informal setups in our department, which work overall because most people are open to having you schedule a meeting or walk in and ask some questions. If you find a department where that's not the case, try to get something more formal. Generally, someone in a working group you are in may be a good place to start. We also have an informal lunch on the calendar each day where faculty/post-docs may join, which allows you to meet other faculty that you may not directly work with. I have found this immensely helpful to get to know my fellow faculty, or get some advice from senior faculty that have dense schedules I would not feel comfortable sequestering an hour from.

Grants

One of the most asked questions for new junior faculty is about funding. These questions and discussions can be stressful, especially if you have no experience with grants. I had some experience with grants when being a Master's-level statistician, but never from the viewpoint of a PI.

How do Grants work?

Honestly, I'm still not 100% sure. NIH R Grants have different requirements with respect to page limits (https://grants.nih.gov/grants/how-to-apply-application-guide/format-and-write/page-limits.htm), but they are generally between 6 and 12 pages. That seems like a lot but it isn't. Remember, all the aims of the grant, the introduction, the figures, and novelty of the grant needs to go in there. Don't go over the limit; period.

One thing we do in JHSPH Biostatistics is the faculty share written grant proposals. Some of the grants have been funded, some have not been funded but discussed, and some were not discussed. This allows junior faculty who have never been on an NIH panel see an array of grants. I learned writing papers by reading other papers and applying a similar logic structure. I imagine grants are a similar endeavour. Disclaimer, I've never applied for an NIH grant where I was the main PI and the one who did the lion's share of the writing. But when I do, having examples to draw from can help immensely. I have submitted to internal and other grant mechanisms, but not NIH as a PI.

Study sections and that stuff

I will tackle a few simple questions now. At JHSPH, as it is a school of public health, a lot of grants come from the National Institutes of Health (NIH), at many different institutes or centers in the NIH (called ICs). Many of our faculty (not myself though) have received grants from the National Science Foundation (NSF). These tended to be more theoretical, but not always. There are also a number of internal grants at an institution. For example, I have a DELTA grant (https://provost.jhu.edu/about/digital-initiatives/delta/rfp/), which is an internal JHU grant.

Grants have letters and numbers, those letters generally refer to the type of grant it is (see https://grants.nih.gov/grants/funding/funding_program.htm). Many grants you will apply for will be R grants, which stands for research. Particularly for junior faculty, some target Career development awards (K grants, https://researchtraining.nih.gov/programs/career-development). Many faculty target R01 grants, as they are the most common. Junior faculty may be more likely to target R21 grants as well as they are for research in earlier stages.

If you are a postdoctoral fellow, you can apply for a K99/R00 (sometimes called a “kangaroo” grant, https://researchtraining.nih.gov/programs/career-development/K99-R00), which is a “Pathway to Independence Award”. These are similar to R01s in the funding amount usually. They are highly competitive, but the number of eligible applicants is smaller than the number of faculty.

For many sections, there are requests for applications (RFAs) that go out. These are proposals that call for grants that do a specific type of work, tackle a specific subject area, or require specific infrastructure resources. Make sure you're on the mission of the RFA before going forward. In order to do that, you'll want to talk to a program officer. In many respects, these people are similar to project managers in other settings. They have a portfolio of different divisions; this proposal is not their only one. Most program officers (POs) have extensive backgrounds in science, but not always specific to your field or the niche of the RFA. That can cause struggles when discussing some of the importance of your work, but that's a good thing. It's a good thing because the panel of the grant isn't going to be niche people. If the program officer doesn't see how your proposal fits with the RFA, it's highly unlikely the study section will see it either. Also, the program officers look at a number RFAs other than this specific one, which allows them to maybe identify other sections or RFAs where your grant may be more appropriate. Don't harass them, but they are your contact to ask questions and you should use them.

Funding: Direct and Indirects

Grants have direct and indirect costs. The direct costs are the monies needed to do the work, such as salary, computing, data collection/analysis, etc. This is generally how you can fund your salary, your work, students, and/or post-docs. The indirects or indirect costs relate to money in the budget that is not directly related to the work (hence indirect), such as money for office space, staff, heating/cooling, electricity, other institutional requirements/support. The “indirect rate” is negotiated by the school and the funding body (see https://www.hopkinsmedicine.org/research/resources/offices-policies/ora/handbook/appendixc.html for some rates).

Write a lot

I recommend the book “How to Write a Lot: A Practical Guide to Productive Academic Writing”. It's not expensive and it's a short book. Note, this will not teach you how to write well or publish. It's specifically on how to write a lot. As an academic, that's the majority of the job. Writing papers, writing grants, writing letters of recommendation (eventually), writing letters of support (“I'd work on this grant for sure”), writing presentations, etc. Writing a lot can help, even if the writing isn't that great to start. The book also recommends a writing accountability group (WAG). We have one with junior faculty in our department, and it has led to grants and papers that would not have existed otherwise. If you don't have one, start one. At JHU, our faculty development office helps create them and facilitate them if you don't have the ability or pull to start one on your own (https://www.hopkinsmedicine.org/fac_development/career_path/wags.html).

How do you recruit students?

First, students need to know who you are. That means attending departmental events and meetings where there are students. We have a tea time every week where students and faculty share tea. We discuss a number of things: life, pets, that week's seminars, other non-statistics human things. We also have a chili cookoff at the beginning of every academic year so that new students can meet the department. We also have a holiday and end of the year celebration. We additionally have joint faculty/student meetings to discuss departmental matters. We have had off-site retreats approximately every 1.5 years to discuss long-term matters of the department and adjustment to our vision and our mission. Our offices are all on the same floor, so they see us in the halls and know where we sit. If you are in a department where that's not the case, try to be somewhere visible some days a week (like a coffee shop in the building the students are) if possible.

A large resource for recruiting students is teaching the first or second-year courses. These students get to know you, how you work, and you get to know them. They at least know who you are if they are your teacher (hopefully). Thus, in some hard money environments, you may have discussions at interviews about “buying out” of teaching. This can be beneficial to have a discussion about this option, but not teaching may put off some departments and may limit your ability to recruit students quickly. That being said, I find teaching incredibly rewarding, but also extremely tiring. I have never taught a lot in one day and not felt like it took a lot out of me. But I've never seen those days as I “got nothing accomplished”, which has happened with strictly research days at times.

Conferences

At JHSPH, I had the tremendous opportunity to attend a lot of conferences. I like to travel and see places, network and meet people, and don't mind public speaking. All of those traits are helpful for going to conferences, but are by no means necessary. Sadly, some programs allow students to go to one conference over the course of their degree. This sometimes conveys the idea that conferences aren't useful or aren't for students. Both are patently false. You don't need to go to 5 conferences a year to be a successful faculty member. Heck, you don't need to go to any. But conferences are great places to meet people in your field, get your name out there (advertiser), and make collaborations and connections for future projects. Oh, and students definitely do go to conferences (maybe a future post-doc?). To fund the travel, hopefully there are funds in the grant for travel and conferences. If not, you may have money in a discretionary account that you had from a startup package or other means. Our department also will pay for one conference a year for all faculty. If none of those options exist, try your hardest to get a travel award from the conference. These are highly competitive, may be only open to students or post-docs, and will likely not cover all the costs incurred at the conference.

Staff and Administration

Lastly, respect the hell out of your good staff and administration members. My mother was a secretary at a university. She had stories about professors who were not the nicest to staff and that stuck with me. If you think it's hard getting a meeting with a collaborator, imagine trying to organize 5 senior faculty from different departments to get on thesis defenses or filling a speaker schedule where no one answers emails. The administrative may be the gatekeepers to senior faculty calendars or room schedules. They are the glue that keeps things together at times and the oil that keeps the machine running at others.

The administrative team also usually knows the ins and outs of grant submissions and may be the ones submitting the grant. Respect their time. Do not expect them to reply on weekends or after hours unless absolutely necessary. Our admin at JHSPH Biostatistics have made policies about requiring notification that we are submitting a grant a period of time before submission and the faculty agreed. Moreover, most staff and admin have been in the department much longer than you; they know who to talk to, the answers to your questions, and they generally will meet with you and do a Q&A. Most importantly, if you have good people that do not feel respected at their job, they will leave.

Conclusion

Try to find someone who's done well in the environment you're in. That is likely a mentor, but maybe not. Try to have people know who you are. You'll have ideas for research; you'll probably will write grants. Ask successful grant writers for copies of their work to use a starting template. You weren't always an expert on how to analyze data or write papers; it takes practice, help, and usually a template. Like most things, a lot of anxiety and frustration can be mitigated or avoided by having open, frank discussions about expectations, requirements, and getting feedback. Remember, you will likely have to ask for help if you need it, but your department wants you to succeed.

The way people use AI is ruining Reproducible Science Again

The basic premise of this article is this: “Would you accept a paper that did a logistic regression, but did not publish the weights due to intellectual property?”. If you answer yes, then I do not think you will agree with some of the following statements. If so, I thank you for your reviewing service and will let the authors for which I review know who you are to send to you.

If you answered no, my question to you is, why do we accept this for artificial intelligence (AI) models? Here I'm using AI in the broad sense, including machine learning, deep learning, and neural networks. In many of these cases, the model itself is only useful as an object. For example, for a random forest, the combination of the individual trees are necessary to do prediction. It is extremely difficult (likely impossible) to reduce this to a reduced representation that would be useful in a paper to do prediction. In a regression framework, even penalized regression, the model can be shown by a series of weights or beta coefficients. For deep learning models, the number of parameters can explode given the complexity, depth, and representation of the network. When using a convolutional neural network (CNN) to segment or classify images, there can be millions of weights for different areas of an image to get a final result. These weights are impractical to print out in a PDF, text file, or supplemental material as it would take a researcher hours to reconstruct this into the network. Thus, the model weights should be released if the results are to be reproducible or useful on an external data set. I will yield that a CNN can be represented in a figure to some degree and be reproduced, but many times other processing, normalization, augmentation, or other non-shown steps are required for reproducibility.

Why is this Happening?

Frameworks such as Tensorflow, Keras, Theano, and PyTorch make deep learning more usable for all researchers. Fitting these models or predicting output (also called inference) can be done on a number of platforms, including mobile, which makes it highly attractive. Moreover, container solutions such as Docker and Singularity allow the entire system to be preserved on which the model was used. So what's the issue? The growing issue is the use of AI, especially in applications of medical data, is that people are not releasing 1) their data, 2) their code, or 3) the model weights.

Release the Data?

Let us tackle the easiest first: the data. Some data was collected without consent to be released, has protected health information (PHI) that cannot be released under protections such as HIPAA (Health Insurance Portability and Accountability Act). It is completely reasonable for researchers to not be able to release the data. Thus, this is totally valid. I will say if they can release the data, many times it is stated it is “available upon request”, but adherence to this policy is not enforced by many journals as the paper is already published (https://science.sciencemag.org/content/354/6317/1242.1, https://twitter.com/gershbrain/status/1207677210221527045) . If authors simply ignore these requests, there can be little ramifications. This may be understandable, because the downsides to the researcher of releasing data, as 1) users could find issues (may be a benefit), 2) it may require maintaining data usage agreements, or 3) many think of this as “intellectual property”, which I will address now.

Release the Code?

Many people, seeing how well AI is working in their application, think that their method could be turned into a commercial product. This may be valid, but must not be used as a shield against reproducible research. Let's turn to releasing the code. If there is no novelty in the framework they used, such as an off-the-shelf VNET, then the code should be released as nothing is “secret”. Even with slight adaptations, unless large and completely new, the code should be released. Many state that if it is off-the-shelf, why would code need to be released? The reason is that although most off-the-shelf methods are used, getting the data into the correct way before running them, including data processing and checks, need to be available. Thus, these “ancillary” scripts are actually crucial for research and reproduction. Even if the architecture is completely novel, it will likely be described in detail in the publication, and thus potentially could be released. Let's assume though that you cannot release the data or the code.

Release the Model?

Lastly, releasing the model. Again, the “model” in this setting can be a complex set of trees or weights, amongst other things. It's uncertain as to whether PHI can be recovered from these models, which is a valid concern given the data cannot be released. I assert that after many discussions that many don't release the model because it is “proprietary” or has potential “intellectual property” that can be commercializable, which I don't disagree with. What I disagree with is that many applications will not fit the requirements for a patent, as slight changes to an algorithm can classify it as a different algorithm. Using these models in a software-as-a-service (SaaS) framework could potentially be profitable, but it's doubtful this will ever happen. Moreover, there is no time limit on these commercializations. Therefore, you claim this can be commercialized, but after 5 years no progress is made, then is it really going to be commercialized or simply an impediment to reproducible and progressive science. If a model fits in the cloud but never comes down, is it a model really at all?

Any Solution?

So what's the answer? I don't know. But here's some help in reviewing.
Personally, I have been putting in boilerplate concerns with a number of medical imaging AI projects, which hopefully you may be able to use:

• Overall, the other main concerns are 1) the data is not available to determine quality, 2) no software is available to test or apply this methodology to another data set, and 3) the segmentation/detection results were not directly compared to any of the methodology for segmentation previously published.
• Releasing the code for processing and modeling, including the final model weights would greatly increase the impact for this paper is highly encouraged.
• Are the data released anywhere? Will it be made public? Will the segmentations/classifications?

I've had authors and editors give the concerns above, which I have yielded to in some cases. I don't think these are 100% necessary for publication, but I would like to know the reasons that I cannot reproduce this analysis or use it to learn how to do better science. Until journals make clearer guidance about these policies (instead of omitting them in many cases), I guess I'll just be ice-skating uphill.

R projects may make large files

Introduction

I have an “old” MacBook, it's a late 2013 MacBook Pro. I haven't upgraded because I wasn't a fan of the butterfly keyboards and the top row bar. I'm glad to hear you can now get new MacBooks with the “old” keyboards. Also I don't see large advances in the specs of the machine, but I'll stay with Mac because I love the OS and integration.

That being said, one of the downsides to having an old MacBook is that I'm struggling with space at times. I offload a lot of things to the cloud and my external drive, but I like having things locally. Also, I am a huge fan of the RStudio Packages framework. I would say the RStudio IDE is a must for using R nowadays; at least if you're a new user. RStudio Projects alleviates a lot of the problems of working outside of an IDE, such as switching directories (opening an .Rproj file opens to the root directory and here::here uses this), multiple unrelated scripts open (each has its own session/window), and has additional build tools for package development.

How the RStudio IDE integrates with Package Development

Using the RStudio Projects for Package development is great. The tools integrate with devtools, which changed the game with making a package. RStudio additionally wrapped this functionality to keyboard shortcuts and GUI clicks, along with integration to Git. WHen you are compiling and building a package, the RStudio IDE knows that you should restart the R session because all the packages (and options) you previously loaded should to be reset. Now it doesn't want you losing any saved work, so all the objects are cached, the session is restarted, and the cache is restored.

The issue

One of the downsides with this strategy is that I'm impatient. Sometimes, especially with large packages or objects, the RStudio IDE will freeze. I will wait and get annoyed and kill the process. The overall issue is that the cached data is not cleared away. The data is stored in .Rproj.user folder and can be quite big (100s of Mb) depending on what you had in memory. A lot of other files are located in there that are related to your user state (think the 10 Untitled files you just haven't saved yet, what scripts were open, what was in the Viewer). Most of the time for projects that are packages, I don't need this information so I delete the folder. Don't worry, it'll get regenerated when you open that project again.

What's the point

If you're doing some house cleaning for hard drive space, take a look at the .Rproj.user hidden folders and see how large they are. They shouldn't be much more than 1Mb, and that's even pretty big depending on how much code you have. Either way, hope it gives you some “free” space. I guess I could buy another MacBook but this one works perfectly well still.

Here's a simple script allowing you to see the overall size of the directory. There are some things I couldn't find using file.size or file.info after recursively listing the files, so I just used du.

x = list.files(
  pattern = "[.]Rproj[.]user",
  all.files = TRUE, 
  include.dirs = TRUE, 
  recursive = TRUE,
  no.. = TRUE)
dir.size = function(path) {
  res = system(paste0("du ", shQuote(path)), intern = TRUE)
  ss = strsplit(res, "\t")
  ss = sapply(ss, function(x) as.numeric(x[1]))
  sum(ss)
}
sizes = sapply(x, dir.size)

Tips for a Job Search (Academic Edition)

After going to a few interviews last cycle for assistant professor positions, I figured I should write on some of the points that I found relevant and general. Some of these were tips given to me, some of them are my own. All these represent my opinions and mine alone.

This will be a least a 2-part series, so I will have an update in the coming week or so.

Full disclosure, I did not receive a tenure-track position offer, so take these with a grain of salt. Most of the materials I had sent out are located on my GitHub and website. I found that most people ask previous applicants/students of your advisor/fellow graduate students for copies of their statements, but I feel like these should be more open and editable, so I published them online for our (and other) students.

My Packets/Materials

My CV is located here and my research/teaching statements and my cover letter for academia is located here.

Step 0: Academic or Industry

One of the first things you should think about or know is whether you are looking for academic or industry tech. I chose to apply for academic positions as well as biotech/tech jobs. Not all my peers chose this, but I will tell you why I did:

1. Academic and Industry turnaround time is different.
   1. Academic applications are due around November (get them done in October), but you should be applying around early or mid October as November is somewhat late for applications.
   2. Although you apply in November for these jobs, you have time as institutions will not get back to you until January through March.
2. Both academic and industry offer good jobs. They have pros and cons (which I won’t list here), but they both afford a solid lifestyle and usually some variety at work.
3. There were a lot of positions in academia open (2016).

Let’s say you want to apply for academia. The rest of this post will be discussing an academic job search and future posts will be on industry searches and also aspects of an interview.

Now you’ve kept the door open for academia, you should know if you are looking more for a teaching gig or research gig. They have vastly different responsibilities and soft/hard money ratios. No one has defined FTE (full time effort) explicitly for me, but I have heard it range from 50-60 hours/week for an assistant professor.

From what I have seen, a “soft” money department requires 70-80% of your salary (FTE) to be covered by grants and the rest from the department (20-30%). These tend to be 12-month appointments. Many biostatistics departments, especially those in a school of public health, fall into this category.

A “hard” money department can range from 50-100% FTE covered from the school, which generally comes from teaching more courses. These are generally a 9-month appointment, where the 25% of the remaining salary (in the summer) comes from grants. Statistics departments and biostatistics departments in schools of medicine can fall into these categories.

Each type of department has their own pros and cons and each department is different.

Timeline

You should probably get applying to many academic institutions around mid-October to early November. Mid-November (although they will not likely be reviewed for quite some time) is a little late in the game. A lot of planning for visits goes on and you want a to be invited and it’s hard for a place to invite you if they’ve filled a lot of “yes” invitations in the future.

Step 1: Your Packet: Academia

Let’s assume you are applying to academia. First thing you need to do is make your packet.

Here’s what you’ll need:

Curriculum Vitae.

This is the most important part. This is your “abstract” or your first impression on a committee most times. It must be updated, formatted well, and have all the relevant information. I remember a professor noting “Someone is going to take 2-3 minutes on a CV. They will go through 20-30 in a session. You need yours to be top-notch.”

Let’s look at the items.

1. Name, website, email, phone number (optional but recommended). Any blog/social media (Twitter)/GitHub pages. You may want to include preferred communication (phone vs. email).
2. Eduation: What school and department your are attending. Include advisor(s), expected graduation date and if you have defended (people will ask), areas of research, dates attended. I have seen people include GPAs and others have not.
3. Previous education: Master’s/Bachelor’s – same as above but I have seen GPAs more commonly here.
4. Relevant (Research) Experience – not cutting grass in 11th grade. Also, usually limit to the last 10 years unless you have done a lot before that. Put pointed deliverables in the text about what you did/how you added value/why it matters to the reader.
5. Teaching Experience. Classes you’ve taught, TA-ed, helped create. Include the professor you worked with (people love talking about mutual acquaintences) and your role. Include short courses/tutorials/workshops you lead, created, or participated as a teacher.
6. Published Publications. Generally descending/ascending by year. Make sure you highlight your name in the author order – people are looking for it. You may want to number them; mine are grouped by year but not numbered. These include in-press publications without the full citation. Make sure you update the citation when the article does get published.
7. Submitted Publications – these are submitted or under review but not accepted yet. These give people an idea of what you are currently working on and how many projects you work on at a time, though it may be a bad measure of that.
8. Talks/Presentations/Posters. Include all the talks you have given, including those at your own institution. Gave a talk at a conference? Include it. Working group? Include it. Journal club? Computing club? If it’s a presentation in front of others the projector is on, include it. Some separate posters and talks, but I included them together. Include the conference name or event.
9. Working Groups. Maybe you work with a group or are on a training grant, but you don’t have publications from it – still add it. People many times know your group
10. Honors/Awards. Win an award for a comprehensive exam or paper in your department? Put it down! ENAR poster award – umm yeah, that’s awesome to put down. If someone shook your hand and you got anything from a shout out in a room, certificate, to money, put it down.
11. Software. Do you release software – make that clear! Put links, say what it does. This includes web (Shiny) applications or any type of apps. Was it in undergrad? So what – put it down. I have had discussions with faculty the entire time allotted just about a web application I did one random weekend not related to my main research.
12. Skills – everyone knows Microsoft Word. Programming languages or other spoken/written languages. Write 1-2 scripts in Python? You’re a beginner not an intermediate. Can you read someone else’s code and know what it does, you’re an intermediate at least (there are other criteria, it’s not set). Do you feel like this i your language and you can speak in it as well as your native verbal language? You’re an expert.
13. Academic Service – I volunteer and I put that stuff down. Any academic job requires “service” (usually of a different sort), but showing you do service outside of reviewing papers, it fits in line with many university missions. Moreover, if you start a club or run a club in your department that is full blown academic service.
14. Additional Experience – things that don’t fit above. Do a hackathon? Put it down here. Say the cool project you did and link to it.

There may be other sections for a CV, but those are mine, save for one. I have a “Research Interests” section at the top that says what I’m interested in/want to do research in. This may be good or bad depending on your view. It may become an reason to put you in the no pile before reading, but I think it’s useful.

Remember, academic search committees are looking for someone who can 1) do research, 2) teach, and 3) perform academic service, e.g. mentoring students, serving on thesis committees, serving on other committees (seminar committee, student recruitment, job search commmittee).

Research Statement

Depending on the position you are interviewing for, the teaching statement or research statement is likely to be the first thing read after your CV. That means you should spend a bit of time on it. Like grants, I hear the best way to write one is to get someone else’s who has been successful. Ask previous post docs, your advisor (though it may be dated), and previous students who have graduated for their statements.
I do not think I have been overwhelmingly successful in getting job offers, but I put my research and teaching statement on GitHub.

I have a few guidelines for what I would include in your research statement:

1. Your philosophy on research.
2. What you want to do in the next 5 years.
3. Why institution X and position Y is the place to do it.

“The Professor is in” has some good points in this and this. Check it out.

Teaching Statement

In an academic tenure-track job (and most research-track), you will teach. Teaching can afford you discretionary money in research track and is expected in tenure-track as a portion of your salary generally comes from you teaching. If you haven’t taught a course, were you a graduate assistant or design something for high school students? Put that down. You should highlight any teaching awards you have had in the past and how they have helped you or what led you to receiving them.

Overall, you should have a philosophy for teaching (at least loosely). As a biostatistician who works with a lot of colleagues who are not statisticians or biostatisticians, I (like to) think that I have the skills to bring the material “down a level” into more understanding terms. I believe there should be transparency in grading and an up-front level of expectation on each side of the classroom. Although I don’t find myself to be the most organized while teaching, I feel that it is an important fact because without it the goals of the class can become out of reach or unclear. Anecdotes may be OK, but used only when directly relevant.

It seemed to me that many research institutions “assume” you are a good teacher and they focus more on discussing your research. There are zero places that will say that consistently good teaching is not essential to their program and your success.

If you don’t have any experience teaching, you should 1) consider getting some and 2) consider again that your job is going to require you to do this. Also, although conferences and presentations are not exactly teaching, you can maybe pepper something in there about you feeling comfortable in front of a room of your (1-year-junior) peers.

Cover Letter

Not all places require a cover letter, but some do and it’s a nice touchpoint to start your packet. Some professors have told me they don’t read them (if they don’t require them) and others do.

I think it’s good to include:

1. Be clear which position you are applying for (most places have multiple)
2. Where you are graduating from.
3. Why are you applying there?
4. How are you qualified.

Letters of Reference/Recommendation

For the people you choose to write you letters of recommendation/reference (I’ll refer to as “letters”), there are no hard and fast guidelines. Except that your advisor should be one of them. This person is the person you (presumably) worked the closest with in the past 4-5 years and they know your strengths and weaknesses best. Moreover, they have likely sat on a committee to hire a new person like you and know how to present your strengths (truthfully) in the best light.

Overall, the goal is ask people early. If a number of students in your department are graduating, they may have too many requests than they can handle in a reasonable timeframe. Some may ask you which places you plan on applying to so that they can maybe make some specific remarks (or a call or 2). Others may ask to see your CV to talk a little bit more about specifics (or to remember exactly what you did).

I worked closely with an non-biostatistician collaborator and I applied to many departments where I’d be working with non-biostatistician collaborators, so I thought he was crucial for a letter. I chose a previous advisor and professors whom I did an extensive project with. You should know who you’ve done work with. If not, check your defense committee again.

Most places you will need 3-4 letters, but have about 5 people you have asked as some places will ask for 5 and some will “allow up to 5”. Make sure you have a file of their full name, email, address, phone number, position, and relation to you (aka advisor/collaborator/etc.).

Step 2: Figure out where the jobs are

For Biostatistics and Statistics, there are some great places to look for jobs online:

• University of Florida
• University of Washington
• Purdue
• AMStat
• SIAM
• Email from AMStat Sections – sign up for them or ask your advisor/friend/colleague to set up a forwarding filter

If you have a place in mind, check out the website for the department. They will have it advertised. Does your membership organization have a magazine? It sounds dated, but a lot of universities still advertise there.

You can also email any of your previous colleagues to ask if their department is hiring. This person should be a persons you would feel comfortable emailing for other reasons.

Check Twitter and social media. Some departments have these and use them to disseminate information. Check them out.

Step 3: Where do you want to live for the next 6 years?

The number one question you should be able to answer is “Why do you want to work here”

You should have a solid answer for that question. Period. Everything else is ancillary to that point.

In many tenure-track positions, it’s 6 years to tenure. If you’re doing well, that is. Leaving a position after 3 years is reasonable, but may not reflect well on you and you will inevitably get asked “Why?”. Moreover, it may seem as though you hadn’t thought thoroughly through on the position. While most of these may be ridiculous because people move jobs for a multitude of reasons (such as partners/family/area/weather/…life), the thoughts will exist.

So ask yourself: “Would I be comfortable/happy living in this town for the next 6 years?” Yes, great. Geographic location and a type of living (city vs. suburb vs. rural) are real things in making your decision. It’s also something that goes into offering someone a job. If the applicant seems great on paper and the interview, but seems to hate the surrounding area or “could never see themself living there”, that may be a thing that puts the decision over to a “no”. You’re not a robot and you have preferences, remember that.

After that question is answered, you more importantly need to answer: “Would I be comfortable/happy working in this place for the next 6 years?” – that’s a bit harder to know, but if there is a “No” creeping around there for some reason, that’s not a great sign. That’s not a dealbreaker for not applying, but remember one thing: interviews are draining. You don’t want to put all your eggs in one basket, but you don’t want a big basket of slightly-cracked eggs. Eggs in this metaphor are your “best self” and cracked eggs are OK, but not so great.

Step 4: Filling out an Unholy amount of forms/Sending Emails

Applications are about dotting i’s and crossingt t’s. They have some automation, but a lot of it is still very manual in its entry. You will have to write and copy and paste many documents over and over. Some will have optical character recognition (OCR) to determine information from your CV. If you have a “standard” CV, this will work. Otherwise, you’ll likely get a bunch of misformatted text you need to delete.

You will need to have accounts for each different university separately as they do not share across for information. Even though most of them use Taleo as a backend. More are using LinkedIn as a resource, which may be a good reason to update your LinkedIn to look like your CV. Many of these systems have places for you to put information about your references so remember to have that text file open with each reference’s information.

If the university you are applying to doesn’t have an automated system set up, you may have to send your packet to a search committee chair or an administrator who is listed on the posting. So you’ll email them and you’ll likely forget something, format something wrong, or forget to say what position you’re applying for, so you’ll get to answer a lot of emails.

Regardless, after the packet is signed off and in, you should (in like 3 weeks) send an email just confirming that everything is there. This is especially important if you don’t get confirmation when your letters of reference are submitted. Applications do fall through the cracks and emails do get overlooked. Do not trust any system in place and always double check your confirmation.

Conclusions

This is one post in hopefully a few on some of my (hopefully useful) insights on the process of applying and interviewing for academic and industry positions for a quant/data scientist/data analyst/research professor. Overall, there is a lot of prep you need to do (now it’s October 5). Some of it will be out of your hands (like letters of reference), which is why it’s so important to be ahead of schedule. Much of it is writing and revising, writing and revising, which you should be good at now. The one takehome message is:

Don’t sell yourself short. You just finished a long, grueling process which at times you probably thought you’d fail at. But you didn’t. Maybe not all the things you’ve done is glamorous or earth-shattering, but you did interesting things. You did things that mattered. Remember that and not make others see that and believe it.

Tips for First Year Comprehensive Exams

During our program, like most others, you have to take written comprehensive exams (“comps”) at the end of your first year of coursework. For many students it's a time of stress, which can be mitigated with some long-term planning. I wanted to make some suggestions on how to go about this for our (and other) PhD students.

Start the week after spring break

Again, comps are stressful. You can be tested on anything from the material (ideally) from your first year. Professors can throw in problems that seem from left field that you did not study or prep on. How can you learn or study all the material?

The way to make comps more manageable is to have a long-term studying trajectory. We have 2 weeks after the last exam to study and prep, and that is crunch time. In my opinion, that time should be working on the topics you're struggling with, annotating books for crucial theorems (if you're allowed them in the exam), and doing a bunch of problems. Those 2 weeks is not the time to cover everything from day one. That time comes before that 2 weeks.

The week after spring break (the week before this was published) is a good time to start your timeline. That gives you about 10 weeks to study and prep. You can start from the beginning of the year to the current time, or work backward. If nothing else in the first week, make a timeline of what topics or terms you will cover over what time frame. This will reduce stress so that it breaks the test into discrete chunks of time and discrete courses.

Get Past Exams

What's the best preparation for the comprehensive exam? A comprehensive exam. This may be a bit self-evident, but I know I had the feeling of not knowing where to start. Our department sends us the previous exams from the past 5-7 years. Some are may not be equitable with respect to the difficulty or concepts covered, but I believe more questions are always better.

Vanderbilt has some great exams, as does the University of New Mexico, and Villanova. You can go to the reference textbooks (Billingsley, Chung, Casella & Berger, Probability with Martingales (Williams)) to try some problems from the chapters you covered as well.

Work from the back

My strategy is to map each exam (or 2) to a specific week. I worked on the older exams first and saved (e.g. did not look at) the ones from the previous 2 years until the 2 weeks before the test. I also would set out blocks of time (2-3 hours) to try to an entire section of an exam, simulating the conditions for that portion of the test. I think these are helpful at gauging how well your studying is going.

Make a study group

How can you study or summarize all the material? Well, it's much easier if you have a team. You can also bounce ideas off each other. Moreover, the exams you have don't have an answer key, they are just the problems. It helps having others that can 1) check your work (swapping), 2) give you their solutions if you can't work out the problem, and 3) discuss different strategies for solving the problem.

We had a group separately for each section of the exam (probability, theory, methods). This separation helps because some students are retaking only parts of the exam and can help in some areas but don't want to be working on the sections they do not have to take. It also helps segment time studying so you don't focus only on one area while leaving another area (likely the one you don't like and are not the best at) neglected.

Delegate Study Areas

We separated different topics (letting people choose first) for each of the sections for that week. Of those not chosen, the rest needs to be assigned. The people/small team that was assigned to a topic needed to make concise (2-3 page) documents outlining the most important areas. They would also do a 5 minute presentation to the group about why these are the most important areas. That is the time to ask questions (and be prepared to get some when you present).

At the end of the school year, you have an organized study document If you think your notes from the year are organized, you are likely mistaken. Even if you're highly organized (many people are not), there is usually too much superfluous details relevant to the course/homework/etc and not the material. Split it up and let others weed through different areas while you focus on those you were assigned.

Drop the weight

If someone does not deliver on their delegated task, drop them. If there was an understanding that they would get double next time, fine. But if no discussion was made, they are out of the group. That person is not holding up his/her end of the bargain, are getting help for free, while contributing nothing back. All students are busy, and incorporating that is fine, but must be done before the session and at the time of delegation. Otherwise, that non-delivery will likely become a pattern and hurt the entire group. These are your friends and classmates, and it must be clear that any non-delivery is a direct negative to the group. No excuses excuse that.

Do as many problems as possible

Do problems. Do more. And then do some more. The exam is a set of problems. Knowing the material is essential, but the more comfortable you are with doing these difficult problems in a compressed time frame, the better you are. Many tests up until now may have been collaborative, take home, and shorter. Your comprehensive exam will be a bit different, so you have to prepare yourself. We're talking about practice; it's important (sorry AI).

Conclusions

Overall, the best way to perform well on the comprehensive exams is to learn the material as thoroughly as possible. Ideally, that is done during the course. Topics are forgotten and areas are always not fully understood the first time around. Therefore, a methodical, long-term study plan should be made to tackle the year's worth of material. I think a team is the best format for discussion and delegation, but you MUST do work alone (doing the problems), as the team does not collaboratively take the test. If you follow your plan (while obviously learning the new concepts in class), then you should feel as prepared as you can be. Best of luck. I would like to leave you a quote/clip from the recent Bridge of Spies movie:
“Do you never worry?”
“Would it help?”

A Faster Scale Function

Problem Setup

In recent question on LinkedIn’s R user group, a user asked “How to normalize by the row sums of the variable?”. Now first, we must define what we mean by “normalize” a matrix/data.frame.

One way to standardize/normalize a row is to subtract by the mean and divide by the max to put the data into the [0, 1] domain. Many times, however, users want to perform z-score normalization by doing:
(x – μ)/σ
where μ/σ are the mean/standard deviation of the column (typically the column).

The answer on that forum eventually came down to using the scale command. The scale function is great. It is simple and has 2 options other than passing in the matrix:

1. Center – should the columns have their mean subracted off?
2. Scale – should the columns have their standard deviation divided after/not centering?

Overall, the function is fast, but it can always be faster.

The matrixStats package has some very quick operations for row/column operations and computing statistics along these margins.

Creating Some Data

Here we will create a random normal matrix with each column having a mean of 14 and a standard deviation of 5.

set.seed(1)
mat = matrix(rnorm(1e7, mean = 14, sd = 5),
    nrow = 1e5)
dim(mat)

How fast is scale?

Let’s see how fast the scale function is:

system.time({
    sx = scale(mat)
    })

   user  system elapsed
  0.971   0.285   1.262

That’s pretty fast! Overall, there is not much room for improvement in this case, but it may be relevant if you have a lot of matrices or ones bigger than the one defined here in mat.

Defining a new function

First, we must load in the matrixStats package and the only function we really are using is the colSds.

library(matrixStats)

colScale = function(x,
    center = TRUE,
    scale = TRUE,
    add_attr = TRUE,
    rows = NULL,
    cols = NULL) {

    if (!is.null(rows) && !is.null(cols)) {
        x <- x[rows, cols, drop = FALSE]
    } else if (!is.null(rows)) {
        x <- x[rows, , drop = FALSE]
    } else if (!is.null(cols)) {
        x <- x[, cols, drop = FALSE]
    }

  ################
  # Get the column means
  ################
    cm = colMeans(x, na.rm = TRUE)
  ################
  # Get the column sd
  ################
    if (scale) {
        csd = colSds(x, center = cm)
    } else {
        # just divide by 1 if not
        csd = rep(1, length = length(cm))
    }
    if (!center) {
        # just subtract 0
        cm = rep(0, length = length(cm))
    }
    x = t( (t(x) - cm) / csd )
    if (add_attr) {
        if (center) {
            attr(x, "scaled:center") <- cm
        }
        if (scale) {
            attr(x, "scaled:scale") <- csd
        }
    }
    return(x)
}

Let’s break down what the function is doing:

1. The function takes in a matrix x with options:
   1. subsetting rows or cols
   2. center each column (by the mean) or not
   3. scale each column (by the standard deviation) or not
   4. Add the attributes of center/scale, so they match the scale output.
2. The functions subsets the matrix if options are passed.
3. Column means are calculated
4. Column standard deviations are calculated (using the colmeans) if scale = TRUE or simply set to 1 if scale = FALSE.
5. If the data is not to be centered, the centers are set to 0.
6. The data is transposed and the mean is subtracted then the result is divded by the standard deviation. The data is transposed back.
   • The reason this is done is because R operates column-wise. Let p be the number of columns. The column means/sds are of length p. If one simply subtracted the column means, R would try to do this to each individual column. For instance, it would recycle the p numbers to get to length n (number of rows), and do that subtraction, which is not what we want.
7. The attributes are added to the matrix to match scale output.

colScale timing

Now we can see how fast the colScale command would take:

system.time({
    csx = colScale(mat)
})

   user  system elapsed
  0.231   0.039   0.271

This is a lot faster than the scale function. First and foremost, let us make sure that these give the same results:

all.equal(sx, csx)

[1] TRUE

Better benchmarking

OK, we found that we can speed up this operation, but maybe this was a one-off event. Let’s use the microbenchmark package to

library(microbenchmark)
mb = microbenchmark(colScale(mat), scale(mat), times = 20, unit = "s")
print(mb)

Unit: seconds
          expr       min        lq      mean    median        uq      max
 colScale(mat) 0.2738255 0.3426157 0.4682762 0.3770815 0.4872505 1.844507
    scale(mat) 1.2945400 1.5511671 1.9378106 1.9226087 2.2731682 2.601223
 neval cld
    20  a
    20   b

We can visualize the results using ggplot2 and some violin plots.

library(ggplot2)
g = ggplot(data = mb, aes(y = time / 1e9, x = expr)) + geom_violin() + theme_grey(base_size = 20) + xlab("Method") + ylab("Time (seconds)")
print(g)

What about scaling rows!

If you note above, we did not standardize the matrix with respect to the rows, but rather the columns. We can perform this simply by transposing the matrix, running scale and then transposing the matrix back:

system.time({
  scaled_row = t( scale(t(mat)) )
})

   user  system elapsed
  2.165   0.624   3.398

all(abs(rowMeans(scaled_row)) < 1e-15)

[1] TRUE

Again, we can do the same thing with colScale:

system.time({
  colscaled_row = t( colScale(t(mat)) )
})

   user  system elapsed
  0.426   0.097   0.542

all(abs(rowMeans(colscaled_row)) < 1e-15)

[1] TRUE

all.equal(colscaled_row, scaled_row)

[1] TRUE

And we see the results are identical

Creating rowScale

The above results are good for what we would like to do. We may want to define the rowScale function (as below), where we do not have to do the transposing and transposing back, as this takes may take some extra time.

Again, if we’re about improving speed, this may help.

rowScale = function(x,
    center = TRUE,
    scale = TRUE,
    add_attr = TRUE,
    rows = NULL,
    cols = NULL) {

    if (!is.null(rows) && !is.null(cols)) {
        x <- x[rows, cols, drop = FALSE]
    } else if (!is.null(rows)) {
        x <- x[rows, , drop = FALSE]
    } else if (!is.null(cols)) {
        x <- x[, cols, drop = FALSE]
    }

  ################
  # Get the column means
  ################
    cm = rowMeans(x, na.rm = TRUE)
  ################
  # Get the column sd
  ################
    if (scale) {
        csd = rowSds(x, center = cm)
    } else {
        # just divide by 1 if not
        csd = rep(1, length = length(cm))
    }
    if (!center) {
        # just subtract 0
        cm = rep(0, length = length(cm))
    }
    x = (x - cm) / csd
    if (add_attr) {
        if (center) {
            attr(x, "scaled:center") <- cm
        }
        if (scale) {
            attr(x, "scaled:scale") <- csd
        }
    }
    return(x)
}

Now let’s see how we do with rowScale:

system.time({
  rowscaled_row = rowScale(mat)
})

   user  system elapsed
  0.174   0.016   0.206

all(abs(rowMeans(rowscaled_row)) < 1e-15)

[1] TRUE

all.equal(rowscaled_row, scaled_row)

[1] TRUE

Let’s look at the times for this breakdown using microbenchmark:

mb_row = microbenchmark(t( colScale(t(mat)) ),
                        t( scale(t(mat)) ),
                        rowScale(mat),
                        times = 20, unit = "s")
print(mb_row)

Unit: seconds
                expr       min        lq      mean    median        uq
 t(colScale(t(mat))) 0.4009850 0.4653892 0.6303221 0.6659232 0.7422429
    t(scale(t(mat))) 1.7889625 2.0211590 2.4763732 2.1928348 2.6543272
       rowScale(mat) 0.1665216 0.1789968 0.2688652 0.2228373 0.3413327
       max neval cld
 0.9008130    20  a
 5.0518348    20   b
 0.5138103    20  a

and visualize the results:

g %+% mb_row

Conclusions

Overall, normalizing a matrix using a z-score transformation can be very fast and efficient. The scale function is well suited for this purpose, but the matrixStats package allows for faster computation done in C. The scale function will have different behavior as the code below from base::scale.default:

f <- function(v) {
  v <- v[!is.na(v)]
  sqrt(sum(v^2)/max(1, length(v) - 1L))
}
scale <- apply(x, 2L, f)

If the data is not centered and center = FALSE, the data will be divided by the squared sum of each column (divided by n-1). This may be the desired behavior, but the user may want to divide by the standard deviation and not this squared sum and colScale/rowScale can do that if necessary. I will talk to Henrik Bengtsson (matrixStats author/maintainer) about incorporating these into matrixStats for general use. But for now, you can use the above code.

How I build up a ggplot2 figure

Recently, Jeff Leek at Simply Statistics discussed why he does not use ggplot2. He notes “The bottom line is for production graphics, any system requires work.” and describes a default plot that needs some work:

library(ggplot2)
ggplot(data = quakes, aes(x = lat,y = long,colour = stations)) + geom_point()

To break down what is going on, here is what R interprets (more or less):

1. Make a container for data ggplot.
2. Use the quakes data.frame: data = quakes.
3. Map certain “aesthetics” with the aes to three different aesthetics (x, y, z) to certain variables from the dataset lat, long, stations, respectively.
4. Add a layer of geometric things, in this case points (geom_point).

Implicitly, ggplot2 notes that all 3 aesthetics are continuous, so maps them onto the plot using a “continuous” scale (color bar). If stations were a factor or character column, the plot would not have a color bar but a “discrete” scale.

Now, Jeff goes on to describe elements he believes required to make this plot “production ready”:

1. make the axes bigger
2. make the labels bigger
3. make the labels be full names (latitude and longitude, ideally with units when variables need them
4. make the legend title be number of stations reporting

As such, I wanted to go through each step and show how you can do each of these operations

Make the Axes/Labels Bigger

First off, let’s assign this plot to an object, called g:

g = ggplot(data = quakes,
           aes(x = lat,y = long,colour = stations)) +
  geom_point()

Now, you can simply call print(g) to show the plot, but the assignment will not do that by default. If you simply call g, it will print/show the object (as other R objects do), and plot the graph.

Theme – get to know it

One of the most useful ggplot2 functions is theme. Read the documentation (?theme). There is a slew of options, but we will use a few of them for this and expand on them in the next sections.

Setting a global text size

We can use the text argument to change ALL the text sizes to a value. Now this is where users who have never used ggplot2 may be a bit confused. The text argument (input) in the theme command requires that text be an object of class element_text. If you look at the theme help it says “all text elements (element_text)”. This means you can’t just say text = 5, you must specify text = element_text().

As text can have multiple properties (size, color, etc.), element_text can take multiple arguments for these properties. One of these arguments is size:

g + theme(text = element_text(size = 20))

Again, note that the text argument/property of theme changes all the text sizes. Let’s say we want to change the axis tick text (axis.text), legend header/title (legend.title), legend key text (legend.text), and axis label text (axis.title) to each a different size:

gbig = g + theme(axis.text = element_text(size = 18),
                 axis.title = element_text(size = 20),
                 legend.text = element_text(size = 15),
                 legend.title = element_text(size = 15))
gbig

Now, we still have the plot g stored, but we make a new version of the graph, called gbig.

Make the Labels to be full names

To change the x or y labels, you can just use the xlab/ylab functions:

gbig = gbig + xlab("Latitude") + ylab("Longitude")
gbig

We want to keep these labels, so we overwrote gbig.

Maybe add a title

Now, one may assume there is a main() function from ggplot2 to give the title of the graph, but that function is ggtitle(). Note, there is a title command in base R, so this was not overwritten. It can be used by just adding this layer:

gbig + ggtitle("Spatial Distribution of Stations")

Note, the title is smaller than the specified axes label sizes by default. Again if we wanted to make that title bigger, we can change that using theme:

gbig +
  ggtitle("Spatial Distribution of Stations") +
  theme(title = element_text(size = 30))

I will not reassign this to a new graph as in some figures for publications, you make the title in the figure legend and not the graph itself.

Making a better legend

Now let’s change the header/title of the legend to be number of stations. We can do this using the guides function:

gbigleg_orig = gbig + guides(colour = guide_colorbar(title = "Number of Stations Reporting"))
gbigleg_orig

Here, guides takes arguments that are the same as the aesthetics from before in aes. Also note, that color and colour are aliased so that you can spell it either way you want.

I like the size of the title, but I don’t like how wide it is. We can put line breaks in there as well:

gbigleg = gbig + guides(colour = guide_colorbar(title = "Number\nof\nStations\nReporting"))
gbigleg

Ugh, let’s also adjust the horizontal justification, so the title is centered:

gbigleg = gbigleg +
  guides(colour = guide_colorbar(title = "Number\nof\nStations\nReporting",
                                 title.hjust = 0.5))
gbigleg

That looks better for the legend, but we still have a lot of wasted space.

Legend IN the plot

One of the things I believe is that the legend should be inside the plot. In order to do this, we can use the legend.position from the themes:

gbigleg +
  theme(legend.position = c(0.3, 0.35))

Now, there seems can be a few problems here:

1. There may not be enough place to put the legend
2. The legend may mask out points/data

For problem 1., we can either 1) make the y-axis bigger or the legend smaller or a combination of both. In this case, we do not have to change the axes, but you can use ylim to change the y-axis limits:

gbigleg +
  theme(legend.position = c(0.3, 0.35)) +
  ylim(c(160, max(quakes$long)))

I try to not do this as area has been added with no data information. We have enough space, but let’s make the legend “transparent” so we can at least see if any points are masked out and to make the legend look a more inclusive part of the plot.

Making a transparent legend

I have a helper “function” transparent_legend that will make the box around the legend (legend.background) transparent and the boxes around the keys (legend.key) transparent as well. Like text before, we have to specify boxes/backgrounds as an element type, but these are rectangles (element_rect) compared to text (element_text).

transparent_legend =  theme(
  legend.background = element_rect(fill = "transparent"),
  legend.key = element_rect(fill = "transparent",
                            color = "transparent")
)

One nice thing is that we can save this as an object and simply “add” it to any plot we want a transparent legend. Let’s add this to what we had and see the result:

gtrans_leg = gbigleg +
  theme(legend.position = c(0.3, 0.35)) +
  transparent_legend
gtrans_leg

Moving the title of the legend

Now, everything in gtrans_leg looks acceptable (to me) except for the legend title. We can move the title of the legend to the left hand side:

gtrans_leg + guides(colour = guide_colorbar(title.position = "left"))

Damnit! Note, that if you respecify the guides, you must make sure you do it all in one shot (easiest way):

gtrans_leg + guides(
  colour = guide_colorbar(title = "Number\nof\nStations\nReporting",
                          title.hjust = 0.5,
                          title.position = "left"))

A little more advanced

The last statement is not entirely true, as we could dig into the ggplot2 object and assign a different title.position property to the object after the fact.

gtrans_leg$guides$colour$title.position = "left"
gtrans_leg

“I don’t like that theme”

Many times, I have heard people who like the grammar of ggplot2 but not the specified theme that is default. The ggthemes package has some good extensions of theme from ggplot2, but there are also a bunch of themes included in ggplot2, which should be specified before changing specific elements of theme as done above:

g + theme_bw()

g + theme_dark()

g + theme_minimal()

g + theme_classic()

Conclusions

I agree that ggplot2 can deceive new users by making graphs that look “good”-ish. This may be a detriment as they may believe they are good enough, when they truly need to be changed. The changes are available in base or ggplot2 and the overall goal was to show how the recommendations can be achieved using ggplot2 commands.

Below, I discuss some other aspects of the post, where you can use ggplot2 to make quick-ish exploratory plots. I believe, however, that ggplot2 is not the fastest for quick basic exploratory plots. What is is better than base graphics is for making slightly more complex exploratory plots that are necessary for analysis, where base can take more code to do.

How to make quick exploratory plots

I agree with Jeff that the purpose of exploratory plots should be done quickly and a broad range of plots done with minimal code.

Now, I agree that plot is a great function. I do believe that you can create many quick plots using ggplot2 and can be faster than base in some instances. A specific case would be that you have a binary y variable and multiple continous x variables. Let’s say I want to plot jittered points, a fit from a binomial glm (logistic regression), and one from a loess.

Here we will use mtcars and say if the car is automatic or manual (am variable) is our outcome.

g = ggplot(aes(y = am), data = mtcars) +
  geom_point(position = position_jitter(height = 0.2)) +
  geom_smooth(method = "glm",
              method.args = list(family = "binomial"), se = FALSE) +
  geom_smooth(method = "loess", se = FALSE, col = "red")

Then we can simply add the x variables as aesthetics to look at each of these:

g + aes(x = mpg)

g + aes(x = drat)

g + aes(x = qsec)

Yes, you can create a function to do the operations above in base, but that’s 2 sides of the same coin: function versus ggplot2 object.

 

All code is located on my GitHub for my blog