IRS13 Scientific Report No. IRS-13 Information Storage and Retrieval Test Environment 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. o Suffix `5' Dictionary [OCRerr] Stem Dictionary * Thesaurus Dictionaries o Other Dictionaries used in Cranfield Project 1.0 0.9 - IRE-31 Abstracts ____________________ A p - Crun-11 Abstracts 0.8 - ex ADI1Text [OCRerr] 0 C, [OCRerr] 0.7 N a - *- Cranfield Project*, 0 * - - - - [OCRerr] Indexing1 1400 Z 0.6 [OCRerr][OCRerr]Documents. 0.5 - 0 0 I liii II iii I I I I I II 0A0 1000 2000 3000 4 5 6 7 8 910PO0 Total Concepts in Dictionary *The "Normalized Recall'1 is here computed by a method different from that used with SMART, and the difference in position on the plot is of no significance. Plot of Normalized Recall versus Number of Concept in the Dictionary, Comparing three SMAflT Results with that from the Cranfield Project. Fig. 9.