IRS13 Test Environment 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. I-i I. Test Environment E. M. Keen 1. Introduction The SMART experiments described in this report are conducted in a controlled laboratory environment. Each experiment uses a fixed document collection together with a set of search requests and relevance decisions. Factors involved in the input, analysis and search procedures may then be varied, and results which are usually based on performance measures are obtained. This section describes and contrasts the several test environments in use, and introduces the test experiments that are described in subsequent sections of this report. 2. Document Collections and Search Requests Three different document collections are currently in use, and a general description appears in [1]. For convenience, the main properties of the document collections and search requests are given in Fig. 1. The IRE-3 collection isan amalgamation of the 405 document IRE-l and 375 document IRE-2 collections previously used for the first experiments with SMART. Documents in this colLection cover most of the subjects in the area of computer science that were current during 1958-196-2; and the abstracts were commercially prepared in order to provide a quarterly current literature `I information service, published in the "IRE Transactions on Electronic Computers The CRAN-l collection is part of the collection used in the second Aslib Cranfield Project. The original documents are research reports and