IRS13 Scientific Report No. IRS-13 Information Storage and Retrieval 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-i8 50 Frequency `00- Aver[OCRerr]e ISO Concept 200 Frequency 250 300 Over All 350 Concepts 400 Per 450 Request 500 Generality 2- Number of 4 Relevant 6 8 Documents I0 12 33 Length- Number of Stem Concepts 18 16 14 12 I0 8 6 4 2 a I'' I I I I I I I [OCRerr] I I I I I I I I I I I I [OCRerr] Request A A A A B A A A B A A A A A 9 A 9 A All A 99 9 A B[OCRerr] 99 A B B B 7 I 2514151718649 9121651315911 I 17109106 337911142412 Nui~bers U B Ii Data for the 35 Individual Requests Showing Visually the Correspondence Between Length, Generality and Average Concept Frequency. Fige 8.