CRANV2
Aslib Cranfield Research Project: Factors Determining the Performance of Indexing Systems: Volume 2
Main test results
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.
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FIGURE 4. 202T
Index Language I. 5a (S.T. S)'nonyn[OCRerr]s, Quasi-synonyms.
Exhau[OCRerr]tivity of Indexing 3
Search Rule A
Document Relevance 1 - 4
Number of Documents in Collection 200 (S[OCRerr]5set I)
l[OCRerr]umber of Questions 42 (Subset 2)
Number of Relevant Documents 198
Generality Number
1
2
3
4
5
6
7
8
9
10
ll
12
13
14
15
23.6
DocumeP/t8
Retrieved
Rel. Non-rel.
---.--._.__.___
195 6,126
177 3,565
144 1,613
117 660
73 234
41 69
17 14
6 I
5 1
0 I
0 0
0 0
RecaLl
Precision Fallout
Ratio Hatio Ratio
a/a+c a/a+b b/b+d
98.5% 3.0% 74.715%
89.4% 4.7% 43.465%
72.7% 8.2% 19,666%
59.1% i5.1% 8.047%
36.9% 23.8% 2.853%
20.7% 37.3% 0.841%
s.6% 54.8% o.171%
3.0% B5.7% 0,012%
2.5% 83.3% 0.012%
0.0% 0.0% 0,012%
Coordination)
42 42 42
42 42 42
42 42 42
37 41 41
30 39 39
23 33 33
13 27 27
3 18 18
2 11 11
1 ? 7
0 3 3
0 1 1
IOO
60
J
.J
so
~r
40
\I J
}
\ l
\
i
90
80
70
3O
20
lO
o Io 20 30 40 50 60 70 aO 90 IOO
% PRECISION