The second piece of crucial advice for individuals considering applying for doctoral programs in the sciences here in the United States has to do with a separate letter from the formal application package. The addressee is a faculty member whose research interests align with your own. Or to put it more bluntly, a scientist for whom you can align your own ideas for a thesis with their established research program. The decision on who to select for this letter has been made infinitely easier by the Internet. But, nevertheless, the process takes some very hard work. Suffice it to say, the work is worth it. In my experience, if done well (and assuming you have decent grades and GRE scores) it will double your chances of admission with fellowship support.
So the first part of the research process involves going to the web site of the program (e.g. ours is here). Generally on the web site, you will find a listing of faculty members with a short precis of their research interests. This however is only the start of what you’re going to do in terms of producing a letter.
Look through the list. Besides looking for a match in terms of the science, you’ll also want to look for initial evidence of a successful lab. One very simple piece of evidence is tenure. In general all full professors have tenure. But a tenure-track faculty member (e.g. an assistant professor) can actually be running an even more productive and successful lab. To assess this, you’ll need to dive into Pub Med (web site is here). Search for you potential targeted faculty member (perhaps your future thesis advisor!) and look for the number and quality of publications. Quality is assessed by the impact factor of the journal (but a good sign are articles published in Science, Nature, the Proceedings of the National Academy of Science or one of the Cell Journals–such as Neuron). If your faculty member is more senior, then it’s a good sign that they are the last or senior author on the papers. If your target is junior, then they may either be first or last author, but in general, they shouldn’t be in the middle. Download some of the major articles for a serious read. We’ll get to that shortly.
Search the web now also for the lab’s home page. In most cases, you’ll get an idea of the make-up of the lab, a longer statement of the lab’s interests and crucially usually some photos of the lab members, either individually or as a group. Look carefully at the images–do the lab members look happy?
Now for the most difficult part: read the journal articles that you’ve picked very carefully. Note your questions in pencil along the side and assess the figures critically. Does the science still seem substantive to you? Do the methods seem interesting and doable in and of themselves?
Look at the references. Does the lab mostly cite it’s own work (not a good sign)? Note the major citations and download those papers also from Pub Med. Read them critically also.
Now produce your letter to the faculty member. Express your interest in joining the lab as a graduate student. Crucially, cross-reference, your application package to the program. The letter should address your own scientific interests within the context of the lab’s, it should demonstrate that you’ve read the relevant papers, and it should lay out your own ideas for next steps (potential thesis projects).
If you can, have a friend who is a scientist, read a draft of your letter. Incorporate any suggestions and email the letter directly to the faculty member. Don’t even think about using a mail merge program to send the same letter out to multiple faculty members.
You’ve just massively increased your chances of admission.