What are “ratings”?
OPOSSEM allows registered users to use a 5-star system to ‘rate’ both instructional materials and web links. Users can only rate an item one time. This helps users find materials and links that are considered particularly helpful by other members of the community. No one can see who rated their material or what rating an individual user gave the material or link. This is to reduce measurement error in the rating system. This is similar to the "karma" system on Slashdot (http://slashdot.org) and other user-moderated sites.