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.
Cranfield experiments The Cranfield experiments were computer information retrieval experiments conducted by Cyril W. Cleverdon at Cranfield University in the 1960s, to evaluate the efficiency of indexing systems.