ISR11 Relevance Feedback in an Information Retrieval System chapter W. Riddle T. Horwitz R. Dietz Harvard University Gerard Salton Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. VI-22 with all the updating methods used. The co-occurrence and cosine correlation functions with constant and increasing alpha strategies are a little superior to the sin[OCRerr]le vector matching correlation function and the alpha correlations strate[OCRerr].