Techniques are described for enhancing the reliability of information received from users in various ways, such as by analyzing votes or other ratings supplied by a user in order to identify fraudulent and other unreliable ratings. Such analysis may be based at least in part on prior ratings submitted by the user, such as based on one or more patterns indicating that the user has a bias for or against one or more of various aspects. Unreliable ratings can then be excluded from use in various ways. This abstract is provided to comply with the rules requiring it, and is submitted with the intention that it not limit the scope of the claims.