I’m a rising senior applying for PhD programs this fall, and I’m really worried about rec letters and not sure whom I should ask. Somewhat embarrassingly, this literally keeps me up at night. I know people say to ask whomever knows you best, but I’ve also heard that it’s important to have more senior/famous people write for you or that you shouldn’t ask people you’ve only taken a class with.
I’m applying to statistics/biostatistics PhD programs, but I’m asking her because this doesn’t seem too specific to any field in particular. Of the 4-5 professors below, who might be good to ask? I need three letters total.
1. My thesis advisor (assistant professor), working on a topic in my field of interest. I’m pretty certain I’ll ask him.
2. Professor from last semester who is one of the top researchers in the subfield I’m interested in. I took his grad school class (in subfield of interest) and got an A, and he sent me an email at the end saying I had done very well on the assignments over the semester. I don’t know him that well yet, but I’ll likely meet with him a few times this summer to talk about my research and future plans.
3. Biostats professor from last semester who is very well known, but doesn’t work in the same subfield as I want to. I took his undergrad class and got an A, and he said at the end that I had been a very good participant in discussions.
4. Political science professors (two) I’m RAing for this summer, both assistant professors. The research I’m doing with them is fairly quantitative, so I think it’s still relevant to the programs I’m applying to. I’ll have met with them/done more work directly with them than most of the other faculty above.
I'd really appreciate some help/advice, thanks in advance!