IRS13 An Analysis of the Documentation Requests 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. X-3 per request. The eight most frequently used thesaurus concepts are given in Figure 1, together with the numbers of requests and frequency of use in the collection. More than half the 35 requests use one or more of these 8 concepts. Comparison of request length between the tw3 different preparers shows that person A constructed longer requests than person B; this matter is considered in part SC. B) Important Request Words Since the requests are fairly short and many use words of high fre- quency in the collection, it would be expected that some requests would contain one or two quite important words that are vital to the request demand. For example, request AIS reads "How much do information retrieval and dissemination systems cost?", and request BL[OCRerr] "Automated information mY the medical field". The words "costt' and "medical" are very important in the request statements, and render otherwise general requests much more specific. Since SMART gives weight to each request word in part on the basis of fre- quency of occurrence in the request and collection, these important w[OCRerr]ds are liable to fail to receive the desired weight; this problem is taken up again in part SD. C) Multiple Need Requests. Nearly all requests express the need as a single topic, but two re- quests demand documents on two topics. Request Bl asks for information on both coding and matching in machine systems, and request Al requires information on "titles", meaning journal titles, organization names and presumably their abbreviations; and also "titles" meaning the subject state-