IRS13 Thesaurus, Phrase and Hierarchy Dictionaries chapter E. M. Keen Harvard University Gerard Salton Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. VII-5L+ Performance Differences, + Thesaurus Superior, Collection Input and Evaluation - - Stem Superior Thesaurus Type Measure Cosine Cosine Numeric Logical IRE-3 Abstract Normed. Recall + .03l[OCRerr] + .0290 31+ (Thesaurus-3) Normed. Precision + .0636 + .01+07 Requests CRAN-l Abstract Normed. Recall + .0193 + .0332 1+2 (Thesaurus-3) Normed. Precision + .021+8 + .0559 Requests Text Normed. Recall + .01+27 + .0121+ (Thesaurus-l) Normed. Precision + .0700 - .0156 ADI Text Normed. Recall - .0005 - .0811 35 (Thesaurus-SAl) Normed. Precision - .0132 - .0916 Requests Abstract Normed. Recall + .01+15 + .01+97 (Thesaurus-l) Normed. Precision + .071+3 + .0602 Performance Differences Between Stem and Thesaurus Taken From Figs. 5 and 6 Using the Normalized Measures, Showing the Results for Numeric (Weighted) and Logical Vectors Fig. 32