There are two main criteria for choosing a graduate school advisor, writes Stanford University School of Medicine's Ben Barres at Neuron: scientific ability and mentorship ability.
The first step, Barres says, is to figure out who is a good scientist. While being at a good university and having tenure may seem to be the marks of a successful scientist, he says that that is not always the case. Instead, he suggests that new graduate students look for researchers who "[ask] important questions and [make] mechanistic or conceptual steps forward in answering them." Barres suggests searching through PubMed and other databases like Thomson Reuters and Grants.gov to get a feel for researchers' work, productivity, and funding levels.
To then gauge how good a mentor those researchers may be Barres advises new graduate students to seek out current and former trainees from the labs and ask them whether they enjoyed their time in the lab, whether the lab head spent time with each lab member, and how lab meetings are typically run. In addition, he says to research how people from that lab have moved on — look at the percentage, Barres says, of trainees who now have their own labs.
"As you gauge the mentoring environment of a prospective lab, make sure to ask whether the students are generally happy," Barres adds. "If not, this is a warning sign. I strongly believe that when a talented student is in the right lab, with a good mentor, that going to lab every day should feel almost like being in summer camp."