Eh, doesn't hurt to repeat the advice here
In my (completely personal) opinion, I think thank-you notes are necessary just because profs are taking time out of their day to speak with you. I also think that it's good to reiterate your interest in their labs, if that's the case.
In my case, I had four interviews; two were excellent, one was very close to excellent, and one was so-so. The length, tone, and content of each of the four cards varied by my excitement about their research and my general impressions for the interview. The lab that I ended up liking the least was polite and relevant (I mentioned things that we'd talked about, etc), but not gushing - why would I say that "zomg i absolutely love your research, i would give both my kidneys to work in your lab, etc etc etc
' if I don't mean it? But for the labs that I did
love - damn straight I expressed how interested I was in what they did!
I think general content should be this:
- Thank them
- Mention what in particular you enjoyed about the conversation (hearing more about research? discussing an issue relevant to science and science policy?)
- Follow up on any advice (did the PI tell you to contact someone in particular? Tell them if you've done so or when you plan to do so)
- Any other pertinent details (especially ones that will remind them of you specifically), if such details are natural in the flow of the card
- Thank them again
Sincerely / Best regards / PLEASEACCEPTMETOTHISPROGRAM*,
*I'm joking, don't actually include that.
Don't write them a letter - I doubt they have the time for more than two paragraphs of writing. Keep it as short as you can while keeping it meaningful, but more importantly, keep it to the point
. It's much easier to read 500 words of concise prose than it is to read a paragraph of writing in the style of a philosopher. If the program has multiple interview weekends (especially one after the other), you might also find it helpful to include the date you met somewhere in the card.
If there's a graduate secretary or somesuch who also helped you out in the process (i.e. you sent him/her emails outside of what was necessary or asked multiple questions), it may also be worth sending them a thank-you card
Just my two cents! (again