which subclass of information filtering system was work of John Thomas Riedl
Recommender system A recommender system or a recommendation system (sometimes replacing "system" with a synonym such as platform or engine) is a subclass of information filtering system that seeks to predict the "rating" or "preference" that a user would give to an item.
Joint Probabilistic Data Association Filter The joint probabilistic data-association filter (JPDAF) is a statistical approach to the problem of plot association in a radar tracker, in which all of the potential candidates for association to a track are combined in a single statistically most probable update, taking account of the statistical distribution of the track errors and clutter and assuming that more than one of the candidates is a target, and the rest are false alarms. It is an extension of the probabilistic data association filter which assumes that only "one" of the potential candidates represents an actual target.