CRANV2 Citation indexing and bibliographic coupling 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. - 247 - FIGURE 7.6T Index Language Citation Indexing and Bibliographic Coupling Document Relevance 1-3 Number of Documents in Collection Number of Questions 35 (Subset 1) Number of Relevant Documents 212 Generality Number 4.3 1400 Coupling Strength 1 2 3 4 5 6 7+ Documents Retrieved R el. Non-rel. 139 106 2021 75 759 48 370 38 187 29 102 28 58 Becall Ratio 65.5% 50.0% 35.4% 22.6% 17.97o 13.7% 13.2% Precision Ratio 5.0% 9.07° 11.5% 16.9% 22.1% 32.6% Fallout Ratio 4.124% 1. 549% o. 755% 0. 382% o. 208% o. 118% FIGURE 7.7T Index Language Citation Indexing and Bibliograph Document Relevance 1-2 Number of Documents in Collection Number of Questions 35 Number of Relevant Documents 79 Generality Number 1.6 1400 Coupling Strength 1 2 3 4 5 6 7+ Documents R eirieved Rel. Non -tel. 51 35 843 26 412 12 197 11 105 9 66 8 41 Recall R at io 64.5% 44.3% 32.9% 15.2% 13.9% 11.4% 10.1% Precision Ratio 4.0% 5.9% 5.7% 9.5% 12.0% 16.3% Fallout Ratio 1.720% 0.841% 0. 402% 0.214% 0.135% 0. 084%