Area Background Approaches to the modeling and management of uncertainty and inaccuracy in database and knowledge-base systems can be categorized into two broad categories, quantitative and qualitative . Quantitative techniques use numerical factors for uncertainty, and manipulate these factors to obtain numerical measures for the uncertainty of derived data. Numerous methods based on various mathematical concepts, such as probability theory, fuzzy sets and fuzzy logic, and Dempster Shafer theory of evidence have been developed so far. Disjunctive logic programming and disjunctive databases are also examples of qualitative approaches to the modeling of uncertainty. Then, if desired, a numerical factor of certainty can be calculated for derived data as a function of the reliabilities of the contributing sources, and their nature of contribution.
Some papers are available on-line.
I am preparing a comprehensive bibliography of works on the modeling and management of uncertainty in database and knowledge-base systems which will be made available on the web.