Although I realize its completely subjective, I would assume any program director or department head qualifies. What about professors or associate professors from well-known institutions like BPEI or Wills?
Not necessarily, on either of those. Really it's getting a letter from one of the big names in whatever field. The problem is it is, as you noted, completely subjective. One of the problems is the field. Someone who's a big name in glaucoma is not necessarily a big name for everyone, so you have to count on the review committee having a glaucoma person who recognizes the "big name" (most probably will, but not necessarily). The same goes for every other field.
IMO, big name letters are overrated. Getting a lesser known person who knows you really well and writes a sterling letter that shows it will do more. Even better is having one of the reviewers know the person who's writing your letter. It's always nice when I read a letter if I feel I can just call up the person who wrote it and get "the real scoop". Even if I don't end up doing it, it's nice to know that I can and feel like I'll get an honest answer.
One of the things I see occasionally is that a whole bunch of students will rotate at one program and all get a letter from the "bigwig" there, and then we get 8 identical letters. More often, we'll get 7 identical letters and 1 slightly different letter for the person who truly stood out from the crowd. If you're that one, sure, it helps a lot, but if you're one of the other 7, it really doesn't mean much.
What's worse is if you get a letter from a huge name from a huge program, and I call up that person and say "So what's the scoop on turkdlit?", and the answer is "Who?" That ends up much worse than getting a letter from a lesser known person.
If you want to know who most of the people think of as the big names, flip through a few issues of the throw-away journals, and you'll find many of them.
Dave
