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 CHARACTERISTICS IRE-3 CRAN-l ADI Number of requests, (all requests) 34 42 35 Number of relevant documents: a) grand tota]. 592 198 170 b) range 2-65 1-12 1-33 c) mean, per request 17.4 4.7 4.9 d) median, per request 16 4 3 e) "generality nwnber"* 22.2 23.6 59.2 Number of specific requests 17 21 17 Number of relevant documents: a) grand total 128 63 36 b) range 2-16 1-4 1-3 c) mean, per request 7.5 3.0 2.1 d) median, per request 7 3 2 e) "generality nurnberII* 9.7 15.0 25.8 Number of general requests 17 21 18 Number of relevant documents: a) grand total 464 135 134 b) range 17-65 5-12 4-33 c) mean, per request 25.8 6.4 7.4 d) median, per request 20 6 6 e) "generality number"* 35.0 32.1 90.8 * Generality Number -- Total Relevant Documents x 1000 Total Doic[OCRerr]uments in Collection Data on Documents Assessed as Relevant to the Requests Fig. 3