<DOC> 
<DOCNO> SP500215 </DOCNO>         
<TITLE> NIST Special Publication 500-215: The Second Text REtrieval Conference (TREC-2) </TITLE>         
<SUBTITLE> Appendix A: TREC-2 Results </SUBTITLE>         
<TYPE> Appendix </TYPE>         
<PAGE CHAPTER="A" NUMBER="80">                   
<AUTHOR1>   </AUTHOR1>  
<PUBLISHER> National Institute of Standards and Technology </PUBLISHER> 
<EDITOR1> D. K. Harman </EDITOR1> 
<COPYRIGHT MTH="March" DAY="" YEAR="1994" BY="National Institute of Standards and Technology">   
 
</COPYRIGHT> 
<BODY> 
results - VPI &amp; SU


                      Summary Statistics           J

            Run Number       VTcms2-ful I, manual 1                                          Recall-Precision Curve
            Num of Queries                   50 J                               1
            Total number of documents over all queries 1
            Retrieved:                     50000                              0.8
            Relevant:                      19489
            Reljet:                        5898

Recall Level_Averages
   Recall      Precision
   0.00         0.7524
   0.10         0.5342
   0.20         0.4510
   0.30         0.3828
   0.40         0.3063
   0.50         0.2539
   0.60         0.1817
   0.70         0.1270
   0.80         0.0809
   0.90         0.0496
   1.00         0.0060
rage precision over all
[OCRerr]ant docs
-interpolated   0.2681  J

it Level Averages
Lit      Recall
00       0.3015
20       0.3795
40       0.4320
60       0.4660
BO       0.4986
DO       0.5250
20       0.5421
40       0.5577
60       0.5745
BO       0.5916
DO       0.6021

                               Document Level Averages
                                              Precision
                             At 5 docs         0.6080
                             At 10 docs        0.5760
                             At 15 docs        0.5387
                             At 20 docs        0.5160
                             At 30 docs        0.4913
                             At 100 docs       0.3806
                             At 200 docs       0.2953
                             At 500 docs       0.1882
                             At 1000 docs      0.1180
                             R-Precision (precision after R
                             docs  retrieved (where R is
                             the number of relevant docu-
                             ments))

                                                                       0.6
                                                                 Precision
                                                                       0.4


                                                                       0.2


                                                                         0


                                                                         1


                                                                       0.8

                              Exact             0.3143

                                                                           0.6
                           NORMAL DEVIATE - Fallout-Recall

                         Ol  0[OCRerr]02            0.84 0.98  0
                                                                           0.4


                                                                           0.2  -

                           2                                      0.98

                                                                 Recall

                                                                          0      0.2      0.4     0.6     0.8


                                                                                             Recall


                                                                                       Fallout-Recall Curve

                                                             I     I     I    I

                           1                                       0.84


                           0                                       0.5                   0

                                                                                           0          0.05        0.1         0.15        0.2
                          -1                                       0.16
                                                                                                             Fallout x 100
                          -2                                       0.02


                          -3                                       0.001
                            -3    -2    -1           1     2     3

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