<p>I've read that at least two is good, three is even better...but where's the upper limit? I'm in the process of narrowing down the professors I found for each school...I'm guessing maybe 5 or 6 is probably the most it should be?</p>
<p>I put 3 in each of my SOP’s. I think 6 is way too much, thats like a paragraph by itself. I said “There are numerous groups at X whose research blah blah blah”, and then I mentioned 3 professors and something interesting about their research. Make sure u also mention other great aspects about the school such as special facilities they have that will help with your research or something.</p>
<p>Mine varied from 2-4 generally. One or two had an extra 5th that was briefly mentioned, someone in a slightly different field as I briefly noted that I would also be interested in expanding my horizons into x direction, etc. In retrospect I’d have cut those down to 4 probably.</p>
<p>2-4 is the standard not too narrow that might prevent you from seeming like a good fit and not too broad to make it look like you are just trying to name as many names as possible with the hope that one of them is reading your SOP.</p>
<p>If there are too many professors in a research area to name them all, it might be easier to name the research area instead. I applied to one school that had ~20 tenured professors doing related work. It would have been silly to single out 2-4 of them as potential advisers and ignore the rest.</p>