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.
GSP algorithm GSP algorithm ("Generalized Sequential Pattern" algorithm) is an algorithm used for sequence mining. The algorithms for solving sequence mining problems are mostly based on the "a priori" (level-wise) algorithm. One way to use the level-wise paradigm is to first discover all the frequent items in a level-wise fashion. It simply means counting the occurrences of all singleton elements in the database. Then, the transactions are filtered by removing the non-frequent items. At the end of this step, each transaction consists of only the frequent elements it originally contained. This modified database becomes an input to the GSP algorithm. This process requires one pass over the whole database.