Should You Get a Ph.D.?

I am occasionally asked by students whether they should go to grad school to get a Ph.D.  So much has already been written on this subject that I hadn't felt it necessary to put my opinion in writing, nor did I have any concrete advice.  But reading Duncan Watts's excellent recent article on the subject crystalized my thoughts.

So here, succinctly, is my advice:

Enroll in a Ph.D. program only if you think you'll enjoy graduate school.  Don't enroll just because you think a Ph.D. will help you in your future career.  In other words, don't go to graduate school as a means to an end.

Note: my advice is meant for US students seeking a Ph.D. in the sciences.  It probably applies more broadly.

Yale's computer science building, Arthur K. Watson Hall, where I spent a lot of time in grad school.  Image from here.

My advice may seem obvious, but it's not.  For instance, this would be bad advice for students considering an M.D. -- almost nobody enjoys medical school, but I think few graduates regret having gone.

But there are three main reasons why this is the right advice for grad school.

1. In Ph.D. programs, unlike in many of the professional schools, you're supposed to be doing pretty much what your professors do -- research.  Sure you have to take some classes and get paid less, but chances are if you don't enjoy grad school, you won't enjoy a research career either.  (Going to grad school to pursue a finance career or something unrelated later is doing it the hard way.)
2. Jobs in research, and especially in academia, are scarce, and going to grad school just because you might like a research job later is a very unsafe bet.  So, going to grad school only makes sense if you'd enjoy the research career, and also if you'd enjoy the experience anyway if a research career doesn't work out.  Four to six years of your life is a long time to be miserable.
3. Grad school, unlike professional school, has no end-date.  You finish when you've done enough.  And it's hard to do enough if you're not enjoying the work.  Forcing yourself to sit through anatomy is one thing; forcing yourself to be creative is quite another.

Also, notice that my advice is an "only if."  So even if you might enjoy grad school, you should explore other possibilities.  Research is incredibly rewarding, but also has downsides which need to be considered.

That being said, I don't mean to be negative.  I'm very happy I went to grad school -- I had a great time there and am lucky to keep on getting to do research.  So, if you want to get a Ph.D., go for it.  Just remember to enjoy the journey.

To Boldly Research

In science, at least in computer science, in order for your research to have impact, you roughly have to do one of two things.

1. Solve a known open problem that people care about.
2. Solve a problem you made up and convince others that it’s interesting / important / impactful.

Often, a paper will do a combination of the two. Of course these aren’t the only ways to have impact – you might find a shorter proof of a known theorem, find a connection between fields others haven’t, etc. But discovering something interesting that nobody else has is a common theme.

So research requires some confidence, if not arrogance, to attempt. Successful researchers clearly need to find this confidence, and it’s not something that comes immediately. So I thought it might be helpful, especially to beginning graduate students (assuming any are reading), for me to spell out why I think succeeding in research is not as hopeless as it might first seem.

Lots of people think in the following chain, especially regarding solving known open problems: 1) Famous researcher X attempted this problem and didn’t get anywhere. 2) They’re clearly better / more experienced than I am. 3) Hence, I won’t be able to solve it.

The worst part of thinking this way is that it’s self-fulfilling – if you never make a serious attempt at a problem believing you can solve it, you probably never will. The second worst part is that this reasoning is flawed.

Lets assume that experienced researcher X attempted (but failed to solve) the problem you’re working on; it doesn’t mean that you can’t. There are a couple reasons for this.

1. Famous researcher X is probably working on lots of problems and doesn’t have nearly as much time to devote to your problem as you do. By seriously applying yourself, you might succeed where X hasn’t.
2. The process of doing research is partly random. You might just have an idea that X hadn’t.
3. Some advances may have come out since X seriously attempted your problem. The average graduate student can solve lots of problems Gauss couldn’t solve, and it’s because science has made progress since then. This type of reasoning holds true on much smaller time scales.

There are also things you can do to increase the chances of being successful, or at least I’ve found that these things have helped me.

1. Work on a problem that you’re actually excited about. This will make it much easier to put in the work needed to be successful. If research feels more like work than fun, then you might be doing it wrong.
2. Find a problem that you think you have a chance in tackling. You should be able to feel in your gut if the problem “feels right.” Many problems are indeed too hard to attempt for beginning researchers.
3. Don’t forget you have access to experienced person Y (your advisor) who might give you some insight that experienced person X didn’t have.

Of course I am also still a relatively young researcher, and getting research confidence is an ongoing process -- I still find working on hard open problems (rightfully) daunting. But if you can fool yourself into thinking you can succeed, even where others have failed, you might just turn out to be right.