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. - 250 - 100 90 80 7O R 60 E C 50 A L L 40 3O 2O 10 0 o.oi FIGURE 7.10T Index Language Citation Indexing and Bibliographic Coupling Document I:elevance 1-4 Number of Documents in Collection 1400 Number of Questions 42 (Sub[OCRerr]et 2) Number of Relevant Documents 156 Generality Number 2.7 Coupling Documents Recall Precision Fallout Strength Retrieved Ratio Ratio Ratio Rel. Non-rel. I 95 5495* 60.8% 1.7%* 2 9. 345% 79 1446 i ! 5.1% 2.459% 51 I 50.5% 3 592 32.6% 7.9% 1.o07% 4 36 257 [OCRerr] 23. O% 12.2% O. 437% 5 25 135 ! i 16.0% 15.6% O. 230% 6 18 70 11.5% 20.4% o.n9% 7+ 12 36 7.6% 24. O% O. 065% 0,1 " " ...... r. o ....... % FALLOUT ....... o- 1o0 FIGURE 7.11P RECALL FALLOT PLOT FOR BIBLIOGRAPHICAL COUPLING AND SINGLE TERM INDEX LANGUAGES I. 3. a AND I. 6. a WITH 1400 DOCUMENTS AND 42 AERODYNAMIC QUESTIONS