I'm applying to Ph.D. programs in the biomedical field in the US but I have a question regarding reference letters:

Can I request a reference letter from a co-worker that has no Ph.D. (instead has been working in a research institute for many years) or a professor from my undergrad university (does not have a Ph.D. but has years of experience) and still be valid? Or should I request a reference letter just to researchers that have a Ph.D.?


You can, of course, request a reference letter from anyone. However, the point of having a reference letter is to speak to your ability to succeed in a research program. Because a PhD is a marker of having succeeded in the same program they're recommending you for, it is highly recommended that you get a letter from someone with a PhD.

If these researchers know you well, then their letters can be valuable, but you should make sure to get a letter from someone with a PhD, if you can.

  • 1
    I think this advice is too negative. People look for evidence that you will succeed as a researcher, not, specifically_ as a student. It would depend on the nature of the experience of the letter writers. Especially for the person who worked in a research lab. What did they do, exactly? How well can they judge the candidate?
    – Buffy
    Nov 18 '20 at 20:52
  • @Buffy That's the advice I received, but I tweaked the language a little. Nov 18 '20 at 21:08
  • I was a bit more concerned with your first paragraph than the second, actually.
    – Buffy
    Nov 18 '20 at 21:46
  • The only requisite is that the person who write the letter has a good reputation, scientifically speaking and even as a layman person. It also depends on the letter content, ie on what are the characteristics that the letter emphasises. The director of my research group has merely a high school diploma. And we are not in a scientifically undeveloped country, not really. I mention this rare exception just to show that the title itself doesn't count (perhaps at all).
    – Alchimista
    Nov 19 '20 at 8:30

Yes, if these people can credibly speak about your research ability. Naturally, one is able to talk more credibly about another's research ability if one is also able to conduct research. This isn't dissimilar from how one is only able to comment intelligently on a piece of work is one is also in the same field.

Research ability and a PhD aren't an if-and-only-if relation. It's possible to do research without a PhD (basically applies to all PhD students), or get a research job without a PhD. But if one has a PhD then one is basically guaranteed to be able to do research.

In the same way, if you ask someone without a PhD to write a reference letter attesting to your research ability, they might not know what to say.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.