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. Evaluation Hierarchy Hierarchy-3 Thesaurus-3 Collection Input Measure Search Dictionary Dictionary Normed. Recall .9437 .9268 Abstract Normed. Precision Parents .7600 .7382 Normed. Recall .9269 .9268 Abstract Normed. Precision Sons .7129 .7382 IRE-3 34 Normed. Recall .9220 .9268 Reguests Abstract }3rothers Normed. Precision .6972 .7382 Normed. Recall .9229 .9268 Abstract Normed. Preci[OCRerr]ion Cross Refs. .7134 .7382 Abstract Normed. Recall All Relations, .9446 .9268 Normed. Precision (Parents, Sons, .7506 .7382 Brothers and Cross Refs.) All Hierarchy runs use a weight of 1.0, and expand both requests and documents Performance Results Comparing Thesaurus and Hierarchy Dictionaries for Five' Results using Cosine Numeric on the IRE-3 Collection, and Normalized Recall and Precision Fig. 20