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. - 161 - FIGURE 4. 800T Index Language III. 1.a (Controlled terms. Basic terms. Exhaustivity of Indexing 3 Search Rule A Document Relevance i - 4 Number of Documents in Collection 200 (Subset I) Number of Questions 42 (Subset 2) Number of Relevant Documents 198 Generality Number 23.6 Coordination) Coord- Documents RecaLl Precision Fallout ination Betrieved Ratio Ratio Ratio x y z Level Rel. Non-tel. a/a+c a/a+b bJb+d 1 174 2,884 87.9% 5.6% 35.170% 42 42 42 2 136 946 68.7% 12.6% 11.534% 42 42 42 3 79 213 39.9% 27.1% 2.597% 31 41 41 4 36 49 18.2% 42.4% 0.597% 20 34 34 5 17 7 8.6% 70.8% 0.085% 6 24 24 6 5 3 2.5% 62.5% 0. 037% 3 13 13 7 2 2 1.0% 50.0% O. 024% 2 8 8 8 1 1 o. 8% so. 0% o. Ol 2% 2 4 4 9 0 0 0 3 3 9o 8o 3o 0 I0 20 20 IO \ \ 30 40 50 60 70 °/o PFLECISION FIGURE 4. 800P INDEX i,ANGUAGE III. l. a 80 90 ioo