Dr. John D. Cook, freelance consultant and blogger There are basically two reasons to get a Ph.D.: personal satisfaction, and credentials for a job requiring a Ph.D. ... If a professor has never worked outside of academia, I’d be skeptical of anything he or she says about “the real world.”

Dr. Paul Rubin, professor emeritus If you do not enjoy doing research, pursuing a Ph.D. will be difficult, unfulfilling and possibly pointless (since you will not want a job with research expectations). ... Having both a masters and doctorate in mathematics is no better than having just a doctorate.

Dr. Eric Jonas, postdoc and serial entrepreneur My best advice to an undergraduate curious about the “experience” of graduate school is: work in a lab while you’re an undergrad. ... A lot of people think of a PhD as being like an undergraduate degree in that you’ve “learned a lot of material”. This is false.

Mr. Carl Vogel, Data Scientist The world is full of miserable grad students. ... Successful grad students aren’t like normal humans.

Dr. Melissa Santos, data scientist To some extent, the process of getting the Ph.D. helped me have the mindset of putting together methods and being creative in my approach to problems that I’m not sure I would have with just the masters degrees. ... The only reason you HAVE to do a Ph.D. is to become a professor.

Dr. Paul Harper, professor of operations research A very common misconception is that applicants can simply pick a supervisor of their choice, but this requires mutual consent. ... Perhaps the best way to summarise the life of a Ph.D. student is to look at the awesome Ph.D. comics (phdcomics.com) by Jorge Cham, which are spot on

Dr. Laura McLay, professor of operations research It’s important to think about how a Ph.D. fits in with other life decisions. I definitely felt like it would be hard to go back to graduate school if I started another career ... Let me be clear: a Ph.D. is not a Masters degree plus a little more coursework and a small project.

Mr. Mike Nute, recovering actuary and Ph.D. student More specifically, if you don’t think that getting the Ph.D. is going to be fun on its own, then there’s a strong chance you’ll be miserable and it will end badly. ... This reinforces the last point above: the only real reason to do a Ph.D. program is for love of the subject.