No different than with Wikipedia, people should be cautious of Knol's postings for accuracy and potential extraneous motives. Different than Wikipedia, modifications to the articles on Knol can only be done by the original author. Anyone with a Knol account can suggest changes, but the ultimate power rests with the author of the piece.
To view Kevin's piece on motivation go to http://knol.google.com/k/motivation-and-behavior#
For a complete listing of psychology related articles on Knol go to http://knol.google.com/k/psychology-knol-index#