[ChrisBennet]

Joel Spolsky had a nice article on performance reviews.

http://www.joelonsoftware.com/articles/fog0000000070.html

Excepted from his blog:

"The effect of reviews on morale is lopsided: while negative reviews hurt morale a lot, positive reviews have no effect on morale or productivity. The people who get them are already working productively. For them, a positive review makes them feel like they are doing good work in order to get the positive review... as if they were Pavlovian dogs working for a treat, instead of professionals who actually care about the quality of the work that they do. "

-Chris