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. IX-29 Minimum Frequency Maximum Frequency 25 50 100 none none .2991 3 .2840 .3051 .3126 .3070 6 2933 .3162 .3148 .2887 10 .2838 .3123 .2970 .2561 a) Rank Recall for Different Frequency Ranges Minimum Frequency Maximum Frequency 25 50 100 none none .4642 3 .4684 .4823 .4756 .4647 6 .4711 .4888 .4738 .4453 10 .4488 .4737 .4567 .4179 b) Log Precision for Frequency Ranges Rank-Recall and Log Precision for Various Frequency Ranges Table 9 All runs with cosine correlation, cutoff 0.6, expansion weight 1.0