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. - 246 - FIGURE 7.4T Index Language Citation Indexing and Bibliographic Coupling Document Relevance 1-4 Number of Documents in Collection Number of Questions 35 (Subset I) Number of Relevant Documents 287 Generality Number 5.9 1400 Coupling Strength Documents Retrieved Recall Precision Fallout Rel. Non-tel. Ratio Ratio Ratio I 195 11658 2 67.9%* 156 3068 i. 6%* 23. 792%* 3 54.[OCRerr]% 115 1152 4.8% 40.1% 6,261% 9.1% 2,351% 4 79 464 5 27.5% 56 299 14.5% 0. 947% 6 19.5% 43 174 15.0% 15.7% 0.610% 19.8% 0.355% 7+ 40 101 13.9% 28.4% 0. 206% I00 90 8O 6O -J 30 20 I0 0 IO FIGURE 7.5P x Fig. 7.2T o Fig. 7.3T + Fig. 7,4T ~9 20 30 40 50 60 70 80 90 IOO [OCRerr]* PRECISION PLOT OF PERFORMANCE WITH BIBLIOGRAPHIC COUPLING FOR SETS OF 42 AERODYNAMIC QUESTIONS, 42 STRUCTURES QUESTIONS and 35 SEVEN-STARTING-TERM QUESTIONS,