ISR11 Relevance Feedback in an Information Retrieval System chapter W. Riddle T. Horwitz R. Dietz Harvard University Gerard Salton Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. VI-28 INDEX OF FIGURES Figure 1 Ranks of Relevant Documents After Each Update as a Function of the Number of DocumentsReturned in Answer to a Ouery Page v'-30 Figure 2 Typical Results of Ouery Modification Using Relevance Feedback Information in the Case when the Relevant Documents are in One Region of N-space Figure 3 The E.[OCRerr]fect of Negative Weightings Applied to Non- Relevant Documents which Consistently Appear on the Output List vTith a Relatively High Correlation VI-30 VI-31 Figure 14 Successful Use of Negative Weighting VI-32 Figure 5 Unsuccessful Use of Negative Teighting VI-37 Figure 6 Results of Various Pro[OCRerr]essions of Alpha Figure 7 T'jpical Results of Ouery Modification Using Relevance Feedback Information in Case when the Relevant Documents Split into Two Regions in N-Space Figure 8 Shifting of Queries in IT[OCRerr]Space Due to Query Modifi- cation Using Relevance Feedbac[OCRerr] Info[OCRerr]nation VI142 [OCRerr]-145 vi-146 Figure 9 Selected Results Sh[OCRerr]7ing Various Effects of the Negative Weighting Heuristic Method vi-148