Using Probabilistic Relational Models for Collaborative Filtering

Recentprojectsin collaborativefiltering andinformationfiltering addressthetaskof inferring userpreferencerelationshipsfor productsor information.Thedataon which theseinferencesarebasedtypically consistsof pairsof peopleanditems.Theitemsmaybeinformationsources(suchaswebpagesor newspaper articles)or products(suchasbooks,software,movies or CDs). We areinterestedin makingrecommendationsor predictions.Traditionalapproachesto theproblemderive from classicalalgorithmsin statistical patternrecognitionandmachinelearning. The majority of theseapproachesassumea ”flat” datarepresentationfor eachobject,andfocuson a singledyadicrelationshipbetweentheobjects. In this paper , we examinea richermodelthatallows us to reasonaboutmany differentrelationsat thesametime. We build ontherecentwork onprobabilisticrelationalmodels(PRMs), anddescribehow PRMscanbeappliedto the taskof collaborati vefiltering. PRMsallow usto represent uncertaintyabouttheexistenceof relationshipsin themodelandallow thepropertiesof anobjectto dependprobabilisticallybothon otherpropertiesof that objectandon propertiesof relatedobjects.