IRS13 Scientific Report No. IRS-13 Information Storage and Retrieval Evaluation Parameters 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. 11-10 Recall Precisio[OCRerr] after retrieval of n documents C 0 (0 0, Number [OCRerr] (x = Relevant) Recall Precision 1 588 x 0.2 1.0 2 589 x 0.[OCRerr] 1.0 3 576 o.'4 0.67 [OCRerr] 590 x 0.6 0.75 5 986 0.6 o.6o 6 592 x o.8 0.67 7 9si[OCRerr] o.8 0.57 8 988 o.8 0.50 9 578 o.8 o.[OCRerr]4 10 985 o.8 0.[OCRerr]0 11 103 o.8 0.36 12 591 o.8 0.33 13 772 x 1.0 0.38 l[OCRerr] 990 1.0 0.36 1.0 0.8 0.6 0.4 2 31<> 5 12 [OCRerr]I[OCRerr]4 0.2 25 0 Q2 0.4 0.6 0.8 1.0 Recoil Result of Cran-l Individual Request [OCRerr]68, Thesaurus-2 Showi[OCRerr] Evaluation Using a Graph of Precision Versus Recall Fig. [OCRerr].