CRANV2 Main test results chapter Cyril Cleverdon Michael Keen Cranfield An investigation supported by a grant to Aslib by the National Science Foundation. Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. - 123 - FIGURE 4. 402T Index Language I. 1 .a (S. T. Natural language. Exhausti[OCRerr]rity of Indexing 2 Search Rule A Document Relevance 1 - 4 Number of Documents in Collection 1,400 Number of Questions 35 (Subset I) Number of Relevant Documents 287 GeneraLity Number 5.9 Coordination) Coord- ination Level 1 2 3 4 5 6 7 Documents Retrieved Eel. Non-rel. 263 (-) 211 6,823* 141 2,442 85 488 43 94 23 20 8 8 Recall Ratio a/a+c 91.7% 73.6% 49.2% 29.7% 15.0% 8.0% 2.a% Precision Ratio a/a+b (-) 3.0%* 5.4% 15.0% 31.4% 53.5% 50.0% Fallout Ratio b/b+d (-) 13. 924 %* 5. o! 3% i. 002% 0. 103% 0.041% 0.016% 35 35 34 25 17 6 3 0 23* 35 35 35 35 35 35 35 35 35 35 35 35 FIGURE 4. 403T Index Language I. 1. a (S. T. Exhaustivity of Indexing 1 Search RUle A Document Relevance I - 4 Number of Documents in Collection Number of Questions 35 (Subset 1) Number of Relevant Documents 287 Generality Number 5.9 Natural language. 1,400 Coordination, ) Coord- ination Level 1 2 3 4 5 6 7 Documents Retrieved Rel. Non-rel. 237 (-) 184 3,532[OCRerr] iii 1,045 54 168 22 19 10 2 5 2 Recall Ratio a/a+e 82.6% 64.1% 38.7% 18.9% 7.7% 3.5% 1.8% J Precision Ratio a] a+b (-) 4.9%* 0.6% 24.3% 53.7% 83.3% 71.4% Fallout Ratio b/b+d (-) 7.208%* 2.145% 0.345% 0.039% 0.004% 0.004% X 35 35 34 22 6 5 3 Y 0 23* 35 35 35 35 35 35 35 35 35 35 35 35