For research students major in CS

As stated earlier, the main focus of a Ph.D. is on research. You typically begin your research at the time when you select an advisor. At most schools you pick an advisor sometime after your first year. At CMU, we like you to start research right away, so you pick an advisor within a month or two of starting the program. Research is very different from taking classes. Many students never make the transition between taking classes and doing research – in fact, at most schools only 1/2 of the students who enter the Ph.D. program leave with a Ph.D. (at CMU, about 3/4 endup  with a Ph.D.). Keep in mind that we are typically talking about students who came in with 4.0 GPA’s from their undergraduate program.

Some key differences between classes and research:

In classes, the homework problems all have known answers and the techniques needed for solving the problems have (usually) been introduced in class. In research, you may be working on a problem for years without a clue of whether it is solvable. You will be the one inventing or finding the techniques for solving the problem.

In classes, you are assigned certain problems to work on. In research, you get to pick the problems. In fact it is your job to find good problems. By “good” we mean problems which are “fundamental.” For example, finding a system hack which makes a particular product like Cisco’s Local Director run better is something that Cisco would love, but would not count as fundamental research. However discovering better algorithms for the problem of task assignment of jobs to hosts in a server farm is considered fundamental research. You are also responsible for making sure that no one else has already solved this problem. This typically involves reading hundreds of papers on earlier research in this area.

In classes, if you can’t solve your homework problem, you can always ask other classmates. Even if none of your classmates know, you can ask the professor, who certainly knows the answer. In research, you are often working alone, or at best with you advisor and maybe one other student. You are free to ask anyone in the world for help, but they will typically not be able to help you, since they don’t know the answer either – if they did, it wouldn’t be research. Many students have a hard time with working independently. In classes, you are constantly being given grades and you are constantly being told what to do next. In research, there are no grades. There is some instruction (from your advisor), but mostly it’s up to you to be self-motivated and pro-active.

In the classroom, there is a distance between you and your professor. In research, you and your advisor will work side-by-side. Your advisor will still tell you what to do – give you ideas for problems to work on, assign papers for you to read, give you programming assignments, and often give you a time-line and schedule. However, when you and your advisor are working on a problem together, you will work as equals. You will both learn from each other. You will make discoveries together. Many students are surprised to find that their advisor is very different in research than in the classroom. A professor who is very dry in the classroom and often looks bored and uncomfortable will often become extremely enthusiastic and excited when working on research problems. In the classroom, you hear your professor discuss results which he/she has already worked out. All problems are always solved by the end of lecture. In research, you will watch your advisor think out loud and see how he/she thinks and reasons. Students often find this very exciting. You may find that you think more quickly than your advisor, but your advisor has more ideas than you. Or you may find that you are better at computations or coding, but your advisor is better at proofs or writing or speaking. This surprises many students, who expect their advisor to be better than they are at everything. Don’t pout, this is an unrealistic expectation. As in all of life, you will be most successful if you simply figure out what skills your advisor has that you don’t and work hard at picking up all of those skills without complaining.

When taking classes, you will almost never see your professor alone. When doing research with an advisor, you will typically have 1 hour per week when you meet with your advisor alone. If your advisor is especially busy (remember, professors have to do research, teach, apply for grants, serve on committees, fly around giving talks, etc.) you may only get 1/2 hour a week. If your advisor is a newer faculty, you may get as much as 2 hours per week. It’s your job to plan ahead so as to maximize the utility of your time together.

Keep in mind that no one can give you a complete picture of what research is. The best way to learn what research is, and whether you like it, is simply to start doing it. The earlier the better!