IRS13 Word-Word Associations in Document Retrieval Systems chapter M. E. Lesk Harvard University Gerard Salton Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. 0.9 Indexing *-[OCRerr] Stem Null 0e8 A-A Associutions: Freq. 6-100 0.7 Cutoff .45 Weight 1.0 0.6 C 0 0.5 (0 `1) 0.4 0) 8- 0.3 0.2 0.l I U I 8 I U I I U I 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Recoil Recall-Precision Cruves - Cranfield Collection Comparison of Association and Indexing Fig. 14