which subclass of information filtering system was work of John Thomas Riedl
John T. Riedl John Thomas Riedl (January 16, 1962 – July 15, 2013) was an American computer scientist and the McKnight Distinguished Professor at the University of Minnesota. His published works include highly influential research on the social web, recommendation systems, and collaborative systems.
Discovery system A discovery system may be an artificial intelligence system (in the context of computer science, logic, and mathematics) or a bibliographical search system (in the context of library and information science).