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-35 Evaluation Number and Percentage* Collection, Input Measure Used of Individual Requests ______ and Thesaurus Type To Determine Phrases Thesaurus Both Merit Superior Superior Equal IRE-3, Abstracts, Normed. Recall 23 67.6% 11 32.4% 0 Thesaurus-3, 34 Requests Normed. Precision 24 70.6% 10 29.4% 0 CRAN-l, Abstracts, Normed. Recall 11 31.4% 24 68.6% 7 Thesaurus-3, 42 Requests Normed. Precision 15 40.5% 22 59.5% 5 ADI, Text, Thesaurus-l, Normed4 Recall 16 55.2% 13 44.8%' 6 35 Requests Normed. Precision 17 58.6% 12 41.4% 6 Hierarchy Thesaurus Superior Superior "Parents" Normed. Recall 17 50.0% 17 50.0% 0 Normed. Precision 17 50.0% 17 50.0% 0 IRE-3 Abstracts, Thesaurus-3, 34 Requests "All Relations" Normed. Recall 13 38.2% 21 61.8% 0 Normed. Precision 11 33.3% 22 66.7% -ffij * Percentages do not include cases where both dictionaries have equal merit Comparisons of Individual Request Merit Giving the Number of Requests Favoring Thesaurus and Phrases, and Thesaurus and Hierarchy, according to Merit Assigned by Normalized Recall and Precision Fig. 24