IRS13 Scientific Report No. IRS-13 Information Storage and Retrieval An Analysis of the Documentation Requests 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. xJ+o Precision 0.6 - 0.5 - 0.4 0.3 - 0.2 - 0.1 - Word Stem Dictionary Thesaurus Dictionary Result of Stem for 10 Requests, and Thesaurus for 25 Requests, Simula- ting Perfect Pre-search Choice I Recall 0.8 1.0 y I I I 0 0.2 0.4 0.6 ADI Abstracts, "Pseudo-Cranfield" Cut-off, Macro Evaluation of 35 Requests. C[OCRerr]parison of Perfect Pre-search Choice of Two Dictionaries with each Dictionary Used Exclusively. Fig. 23.