The topic of your thesis is one of the most important elements of your graduate career. This will determine the research community you’ll become a part of, the “brand” you’ll job hunt with, influence grant applications, and will be the focus of a major part of your career. It’s possible to change your research direction, this is most easily done after getting tenure or between your Masters and your Ph.D., but doing so would be a setback.
This is a decision that is very useful to get right.
Beyond the pragmatic elements of your research area, you need to find something that is interesting enough to you that you can pour thousands of hours into it without getting bored. I changed sub-fields between my Masters and Ph.D. After studying the first area for 16 months, I knew I didn’t have the enthusiasm to pour 4 more years into it.
Because it is such a major time investment, I think it’s a mistake to enter a “trendy” field. Firstly, it might not be so trendy by the time you’ve finished your studies, but secondly, it is hard to do good work in an area that you aren’t passionate about.
Situations Where Picking A Thesis Topic Is Easy
You enter graduate school focused on a specific topic
Most graduate applications ask about your proposed research project. This isn’t meant to be a firm commitment on what you’ll study but is instead intended to give faculty some idea about your interests.
Some students enter graduate school with a clearly defined research project that they’re passionate about pursuing. This makes the choice of thesis topic quite simple.
Your adviser assigns you to a project
For graduate students who are working on part of a larger research program set by their adviser, this is simple too – your thesis will be dictated to you.
A Heuristic For Finding A Topic Yourself
If you’re in the, in my opinion superior, position of choosing your own topic, the freedom and range of choices can be daunting. My suggestion would start in the sub-field you’re situated in, and start reading papers and attending talks. Talk to other students in your group and learn about what they’re working on. If your adviser is willing, talk to them about what you learn from each, what is interesting, and what seems questionable.
Eventually, you’ll find a paper that captures your imagination. Start reading follow-up work the author(s) have done and read through everything it cites and builds on. If it hasn’t been recently published, look for other works that cite it and read them.
If you can find alternative approaches to this foundational paper, read them over and compare the different models or techniques. Send an e-mail to some of the authors, discussing things you found interesting or confusing in their work. Mention follow-up studies and see what they think of them. If they’re willing to send you any pre-prints, have a look at them.
At this point, you’re at the cutting edge of a research area. Work that hasn’t been done is something you can do. This can develop into a research program and ultimately be your Ph.D. thesis.
If you get to a point in the process where you lose interest, go back to the beginning and resume reading papers and attending talks on a variety of topics. Dig deeper into things that interest you.
Overlap With Other Academics
Some researchers early in their careers worry that they’ll end up with “the same thesis topic” as someone else. The step above where you examine all the related work is, in part, to deal with this. Even if two researchers are working on the same question, they will usually be applying different tools to answer the question – both answers and approaches will be useful. It is highly unlikely that two people will stumble onto identical research programs.
Usually, if you find someone working on exactly what you were interested in, in the same way you intended to work on it, this can be a good thing. Instead of duplicating their labor, build on it! Shift your research question and explore a related issue or go further in-depth than they have.
For those who have written a thesis, how hard was it to settle on a topic? What did you find useful when trying to decide?