Not all answers are equally good: estimating the quality of database answers

With more and more electronic information sources becoming widely available, the issue of the quality of these often-competing sources has become germane. We propose a standard for rating information products with respect to their quality, and we show how to estimate the quality of answers issued by databases from the quality specifications that have been assigned to these databases. The annotation of answers with their quality provides valuable information to users and is an important new kind of cooperative behavior in databases. We report on preliminary simulations that were carried out to test the validity of our methods.