For a really excellent, far more comprehensive and much better articulated series of articles pertaining to ratings/rankings, check out www.lifewithalacrity.com <p>Some of the articles include: Using 5 Star Rating Systems, Experimenting with Ratings, Systems for Collective Choice, Rating Systems, Competitive Ranking Systems <p>The ratings users choose are certainly influenced by the presentation of the rating opportunity. The result of forcing "Come on guys rate everything!" down users' throats is that if people really dont have an opinion or feel strongly, most likely they will indicate neutrality. If users have more of a choice about contributing a rating then only the users who have a strong opinion will take the time/effort to complete a rating and so you will end up with a bimodal distribution.<p>The good/bad or star ratings are always useless to other users without the accompanying explanation of the review.
_Let users choose from five stars, and they nearly always pick three_<p>Amazon has the problem of bimodal distributions for their ratings...nearly every user either votes one star (and bitches, "If I could choose zero, I would") or five. They've actually started sending emails to people requesting reviews to fix this problem (to get the silent majority to vote.)<p>