ASSOCIATIVE ADJUSTMENTS TO A DOCUMENT FILE ARE CONSIDERED AS A MEANS FOR IMPROVING RETRIEVAL. A THEORETICAL INVESTIGATION OF THE STATISTICAL PROPERTIES OF A GENERALIZED MISMATCH MEASURE WAS CARRIED OUT AND IMPROVEMENTS IN RETRIEVAL RESULTING FROM PERFORMING ASSOCIATIVE REGRESSION ADJUSTMENTS ON DATA FILE WERE EXAMINED BOTH FROM THE THEORETICAL AND EXPERIMENTAL POINT OF VIEW. THE EXPECTED GAIN IN MISMATCH IS PRESENTED AS A FUNCTION OF VARIOUS MEASURABLE CHARACTERISTICS OF THE FILE, SUCH AS ERROR RATES IN INDEXING AND THE PROBABILITY DISTRIBUTIONS OF THE ASSOCIATIVE ADJUSTMENT CRITERIA. IN A LIMITED SITE PATENT OFFICE FILE WITH A LOW INDEXING ERROR RATE EXPERIMENTAL RESULTS ARE PRESENTED APPLYING (1) NO ASSOCIATIVE CORRECTION (2) THE GENERALIZED MISMATCH WITH NO ASSOCIATIVE CORRECTION (3) ASSOCIATIVE CORRECTION AND (4) QUERY ADJUSTMENT. IN GENERAL THE RESULTS USING THE ORDINARY MISMATCH WITH AN ASSOCIATIVE ADJUSTMENT ARE SUPERIOR TO THOSE USING THE MORE GENERALIZED QUADRATIC MISMATCH OR THE QUERY ADJUSTMENT SCHEME. TWO APPENDICES ACCOMPANY THE REPORT--(1) ASSOCIATIVE CORRECTION FOR UNDERINDEXING BY EDWARD C. BRYANT, DONALD T. SEARLS, AND ROBERT H. SHUMWAY, AND (2) ON THE EXPECTED GAIN FROM ADJUSTING MATCHED TERM RETRIEVAL SYSTEMS BY R.H. SHUMWAY. THIS DOCUMENT IS AVAILABLE AS AD-651-630 FROM THE CLEARINGHOUSE FOR FEDERAL SCIENTIFIC AND TECHNICAL INFORMATION, SPRINGFIELD, VIRGINIA 22151, $3.00 FOR HARD COPY, $0.65 FOR MICROFICHE, 78 PAGES. (AUTHOR/CM)