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. VI 1-12 Input and Type Evaluation Stem Thesaurus No. Collection of Thesaurus Measure Dictionary Dictionary (cosine log.) (cosine log.) [OCRerr] IRE-3 Abstract Normed. Recall .8777 .9067 34 (Thesaurus-3) Normed. Precision .6167 .6574 Requests 14 Cran-l Abstract Normed. Recall .8397 .8729 42 (Thesaurus-3) Normed. Precision .6377 .6936 Requests 22 Text Normed. Recall .7695 .7819 ADI (Thesaurus-3) Normed. Precision .5248 .5092 23 35 Text Normed. Recall .7695 .6884 Requests (Thesaurus-SAl) Normed. Precision .5248 .4332 24 Abstract Normed. Recall .7546 .8043 (Thesaurus-l) Normed. Precision .5221 .5823 Performance Results Comparing Stem and Thesaurus Dictionaries for Five Results using Cosine Logical on Three Collections, and Normalized Recall and Precision Fig. 6