How long does a PhD take?
The question is critically important to current and prospective graduate students. The answer affects their ability to plan their educations, personal lives, personal finances, and careers. Deciding to do a PhD is a little bit like signing a cell phone contract that says how much you owe every month, but not when you get to stop paying. The nature of research means that the duration of a PhD is very uncertain. But, you would be foolish to start one without first learning about how long they take, at least on average. I was foolish like that.
Graduate programs attract students by competing with each other to offer graduate students appealing funding packages. But, graduate students can find themselves racing against the clock to finish their programs before these attractive offers run out. In a UBC PhD program, students who remain in their program after 4 years will find that they no longer have access to the four year fellowships, tri-council funding, or preferred TA hiring that attracted them to school in the first place. I was foolish like that. Perhaps it is necessary to cut students off so they don’t linger in the cushy student life forever. But, it is important to see if 4 years is a realistic goal that most students are actually able to achieve, or if the 4 year funding cliff is an unrealistic expectation that harms typical students for taking typical amounts of time to finish their program.
It is a very legitimate question to ask of an educational institution. Of course, the nature of research means that the length of a PhD is very uncertain. That’s to be expected. But prospective and current PhD students should have a realistic expectation of how long their degrees typically take. How many people take 4 years? How many take 5 years? How many take 6? Obviously, no one takes more than 6 years, UBC has a rule about that. It turns out that students and professors alike have a lot of misconceptions about the realities. It doesn’t help that UBC treats this information like its some kind of big secret.
I don’t know how long PhDs take at UBC. But, I did ask a lot of people, sent a lot of emails, did a lot of reading, analysed some data, and even made Freedom of Information Act requests. After all that, I had a small number of answers that didn’t agree with each other. I also had (I think) a number of people annoyed with me for asking too many questions that (I guess) students aren’t supposed to ask.
I was involved for two or three years (depending on how you count) in my department’s prospective-student-wooing open house. If those are any indication, “How long do graduate degrees take” is being asked by a large fraction of prospective students coming to UBC. The journey you are currently reading about started because I was disappointed with the answers they were getting. I heard a lot of answers from professors along the lines of “2 years for Masters and 4 years for PhDs, although, obviously, a few slackers take 5 years or more.” I didn’t think that was quite consistent with reality.
In fact, it isn’t quite true. But, I don’t think the professors are being intentionally deceptive. I think they selectively remember their all-star students who wrap up in 3 years, and then make excuses for why they shouldn’t include people who take a long time in their average. Student X didn’t work hard. Student Y had health problems. Student Z had to work part time to feed her family. Obviously, those aren’t ‘average’ students who should be included in the average. The problem is that the students are just asking, when they should be saying “show me the data.”
Show Me The Data
Eventually, a friend of mine discovered that UBC actually had some graduate student completion data up on the PAIR website. It has since been placed behind a password (thanks to me: read on, dear reader), but here it is. Since this is a story about how hard it is to find out how long PhDs take, I should mention that the data was in the form of an Excel spreadsheet with 31832 entries instead of something sensible like a database. If you ever want to frustrate someone into not looking at large volumes of data, use Excel.
Here is a description of the data from a representative of FOGS:
The spreadsheet you have been looking at represents a study undertaken using a subset of Admission cohorts – that is taking a subset of each admission years new intake and tracking them to completion. The report you are looking at amalgamates the 1995 – 2003 Admission cohorts and presents the outcomes of these students. For the Outcome, students may have Graduated, Left UBC, Transferred to another program, Still be in Program or are Unknown if we don’t know what’s happened to them.
This data would easily answer my question, except that it has apparently been corrupted. Among lots of other information, it contains three dates: Program start date, Program end date, and graduation date for each student. The amount of time a student spends in their program is the Program end date minus the Program start date. I noticed something funny about this quantity: About 30% of PhD students in the represented cohorts completed their programs in 2 years or less and not a single person in those cohorts completed their program in between 2 years + 1 day and 3.5 years. About 20% of every student who graduated finished in exactly 2 years to the day. There’s a very suspicious gap in the data between 2 years and 3.5 years. I asked FOGS about it. They responded:
[The students who finish in 2 years or less are] likely those that have come from other institutions to complete their studies at UBC or in very structured programs – but the majority graduate in the 4-7 year range (400; 559; 469; 246).
… If you break the TIP Years by CIP Division (the Statscan area of program study) you’ll see that the earlier graduants tend to be clustered in Education and Social Sciences. Social Sciences includes Psychology, a Department that streams students from Masters thru Doctoral levels which helps them complete in a timely (often quicker) fashion…
…It makes sense that very few students would complete in the 3rd year. The earlier 0-2 group are likely either transfers or in uniquely structured programs (ie: Education) where completion may occur more quickly than anticipated. The average time to completion (graduation) is just over 5 years.
Okay, it all makes sense now. Its Education and Psychology students. Except it’s not. Here’s the breakdown for the PhD students who finished their programs in 2 years or less:
10 business & management
75 Health Sciences
96 Social Science
Only 12 transferred from other institutions
This group of students is pretty statistically typical for UBC as a whole. They aren’t more likely to be education students as engineers or scientists or anything else.
The students aren’t demographically unusual in any way, but there is something highly unusual about them as a group: They wait an incredibly long time to graduate after their programs end. Sometimes, they wait almost 10 years. Here is a plot where the vertical axis is how long the student waited to graduate after the end of their program ([Grad date] minus [program end date]) and the horizontal axis is time in program ([program end date] minus [program start date]).
Here is the histogram of the two groups of students. Homework: Use your favourite statistical technique to discover how likely it is they were sampled from the same distribution.
I showed these plots to the above mentioned representative of FOGS and the response from UBC was to not answer me and place the data behind a password immediately so that students could no longer get at it. (No worries, I put it here on the web.)
Freedom of Information
I had hit a roadblock with FOGS and still didn’t know how long PhDs took. But UBC had a report from 2010 with the title “Graduate Student Completion Rates and Times.” Perfect. I asked for it along with another report. Apparently, it is top secret:
I’ve talked with the Dean’s Assistant and neither reports are available for public readings as they contain privileged information.
Of course, when someone from the public requests personal or top secret information, employees of public institutions are required by the Freedom of Information and Protection of Privacy act to inform them that an FOI request must be made to obtain the information. But, I guess they forgot. I made one anyway.
[Spoiler: It will turn out that neither report was top secret.]
FOI Requests and responses:
Request sent March 30, deadline May 17
1. Graduate Student Completion Rates and Times, March 2010, including all appendices
- Report was given June 5.
2. UBC Faculty of Graduate Studies 2011 External Review Self-Study, including all appendices
- Report available on the web. Appendices delivered on July 9th, except appendix 25 disclosure of which may have harmed the business interests of a third party
3. Any draft versions of the report Graduate Student Completion Rates
and Times, March 2010
4. Any raw data used in preparing the report Graduate Student
Completion Rates and Times, March 2010, in machine-readable format
such as a spreadsheet.
- “We were informed that draft versions of this report no longer exist in electronic or hard copy formats, and that the database containing the raw data for this report (drafts and final copy) is no longer available. Recreating that compiled data…would be extremely time consuming and would unreasonably interfere with our operations.”
[UBC: If you lost the data, don’t even fret about it. You can just download it again here.]
5. All records related to the CUPE 2278 union’s bargaining to extend
the preferred hiring preference for TAs. Date range is January 1, 2012
to March 30, 2012.
- 30 day extension requested on June 5
- 535 pages of responsive emails were identified, mostly emails between UBC staff. These were withheld in their entierty because all of them contained advice, recommendations, legal advice, would harm the right to personal privacy or would harm the financial or economic interests of a public body. Fair enough. I didn’t get them on July 9.
6. All records related to graduate student completion rates and times
in the date range January 1, 2012 to March 30, 2012
- “We have been informed that creating these records would involve compiling and analysing data, which would be extremely time consuming and would unreasonably interfere with our operations” June 5
All that work and all I got was some lousy appendices. Well, I also got the report that I wanted. The only really useful thing about it is that it is full of interesting plots like this:
Because FOGS lost the data used to compile this report, I have no way of knowing if it is affected by the problems I discovered above.
So, How Long Do PhDs Take?
It depends who you ask. It may be 4 or 5 years if you ask the professor-on-the-street. It may be just over 5 years on average if you ask FOGS. But, I’m writing this, so I guess we are asking me (i.e. I’m asking me).
I don’t trust FOGS’s data for the reasons outlined above. I believe that there is a problem with the program end date column. Dates in this column may be getting “toggled” prematurely (at or before 2 years) for about 30% of students in the cohort. I don’t know the reason, but the evidence is in the plots above. We can estimate the average completion time by avoiding this column for the corrupted group of students. [Grad date] minus [Start date] is one way, but it doesn’t account for the months that students spend after they finish waiting for a graduation ceremony to happen. We can account for this time by subtracting off the average of ([Grad date] minus [Program end date]) for the uncorrupted group (students who took more than 2 years to graduate). Here is the histogram compared to the one for (Program end date – program start date):
The average time in program according to this is about 5.5 years. This is about 6.5 months longer than the bizarre looking FOGS data would claim. You are welcome to believe FOGS instead of me, but it could cost you about $700 in tuition and a few months of your youth. I was foolish like that. Keep in mind that there are well known variations according to what type of program students are in. By the way, programs where students finish quickly are correlated with programs where students are well funded. I’ll let you think about that.
Is a four year funding model reasonable? At UBC, 78% of PhD students need more time. Is a 6 year hard limit on PhDs reasonable? At UBC, 27% of students need to write a letter explaining why circumstances beyond their control resulted in them being unable to complete their degree in a timely manner. Those percentages only include the students who actually graduate. As we can see in FOGS’s data, many more end up leaving for various reasons.
I have the following requests for my various audiences:
Professors and Staff: Please download the graduation data, analyse the outcomes of students who graduated from your program and post the results where current and prospective students can get it. Then, everyone will have answers tailored to their department.
Graduate students: Please ask for the data when you ask “how long will my graduate degree take?”. Don’t let anyone tell you the answer in words because they really don’t know. Definitely don’t believe any program length indicators that involve someone giving you money (scholarship lengths, preferred TA hiring, etc.).
UBC Representatives: Please return the graduation data to the people of BC. I’m really sorry that I plotted it. In my defence you trained me for way too many years to compulsively plot things. Will you forgive me? Funny looking data is much better than none at all, and people would rather get it from you than from me. Keep new data flowing all the time. This information affects people’s lives. Also, if you have any answers to the questions I’ve raised, please join the conversation in the comments below.