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-14 Word Local Usage1 Local Usage2 Word1 2 km density altitude in earth's density of air in atmosphere atmosphere km 200 altitude in earth's height in km of atmosphere atmospheric phen- omena cold turbo-jet temperature of ex- turbo-jet haust from jet engine models wire models material of which models are built eccentricity contracts ellipticity of contraction of satellite orbit satellite orbit leading edge leading edge of front in shock shock tube front tube Associated Pairs with Local Meanings Fig. 3