<DOC> <DOCNO> IRS13 </DOCNO> <TITLE> Scientific Report No. IRS-13 Information Storage and Retrieval </TITLE> <SUBTITLE> Word-Word Associations in Document Retrieval Systems </SUBTITLE> <TYPE> chapter </TYPE> <PAGE CHAPTER="9" NUMBER="33"> <AUTHOR1> M. E. Lesk </AUTHOR1> <PUBLISHER> Harvard University </PUBLISHER> <EDITOR1> Gerard Salton </EDITOR1> <COPYRIGHT MTH="December" DAY="" YEAR="1967" BY="National Science Foundation"> Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. </COPYRIGHT> <BODY> IX-33 Cutoff Rank Recall Log Precision .30 .3247 .4770 .45 .3409 .4982 .60 .3162 .4888 .75 .3116 .4932 .90 .2933 .4608 All runs cosine correlation, frequency range 6-50 Effect of Varying Cutoff Table 10 </BODY> </PAGE> </DOC>