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-24 Number of Requests with Collection Rank of First Relevant and Input Dictionary 1-2 3-10 >10 IRE-3 Stem 27 6 1 Abstracts Thesaurus-3 30 2 2 CRAN-1 Stem 24 12 6 Abstracts Thesaurus-3 26 11 5 CRAN-l Stem 24 10 8 Indexing Thesaurus-2 27 10 5 ADI Stem 18 8 9 Text Thesaurus-i 21 9 5 ADI Stem 16 9 10 Abstract Thesaurus-i 22 9 4 fe.g., in IRE-3 Abstracts Stem, for 27 of the requests, the first ranked relevant document occupies rank position 1 or 2; for 6 of the requests, it occupies ranks 3 to 10, and for one request it occupies a rank larger than 10[OCRerr] Comparison of Individual Request Merit Giving the Numbers of Requests Achieving Three Ranges of Rank Position to the Best Ranked Relevant, for Stem and Thesaurus Dictionaries and Five Runs in Three Collections Fig. 16