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. THESAURUS- 3 HIERARCHY-BROTHERS o THESAURUS-3 0 * HIERARCHY-CROSS REFERENCES IN PRECISION PRECISION o THESAURUS-3 0 * HIERARCHY-ALL RELATIONS *7([OCRerr]RENTS1 50N51 BROTHERS3 AND CROSS REFERENCES) 0 ~ * [OCRerr] [OCRerr]* o[OCRerr] [OCRerr] 0 * [OCRerr] e 1.0 0.6 - OA - 0.2 - I j I I I ).2 OA 0.6 0.8 1[OCRerr]RECALL0 1£- 0.8 - 0.6 - OA 0.2 I I I I I I I 1RECALL 0.2 0.4 0.6 0.8 10RECALL0 0.2 0.4 0.6 0.8 1.0 Hierarchy Expansion by b) Hierarchy Expansion by cY Hierarchy Expansion by Brothers Cross References Parents, Sons, B[OCRerr]others and Cross References Performance Curves Comparing Thesaurus with Three Hierarchy Searches, IRE-3 Collection Fig. 23