@device(postscript) @libraryfile(Mathematics10) @libraryfile(Accents) @style(fontfamily=timesroman,fontscale=11) @pagefooting(immediate, left "@c", center "@c", right "@c") @heading(A Probabilistic Analysis of the Rocchio Algorithm with TFIDF for Text Categorization) @heading(CMU-CS-96-118) @center(@b(Thorsten Joachims)) @center(March 1996) @center(FTP: CMU-CS-96-118.ps) @blankspace(1) @begin(text) A probabilistic analysis of the Rocchio relevance feedback algorithm, one of the most popular learning methods from information retrieval, is presented in a text categorization framework. The analysis results in a probabilistic version of the Rocchio classifier and offers an explanation for the TFIDF word weighting heuristic. The Rocchio classifier, its probabilistic variant and a standard naive Bayes classifier are compared on three text categorization tasks. The results suggest that the probabilistic algorithms are preferable to the heuristic Rocchio classifier. @blankspace(2line) @begin(transparent,size=10) @b(Keywords:@ )@c @end(transparent) @blankspace(1line) @end(text) @flushright(@b[(26 pages)])