CRANV2
Aslib Cranfield Research Project: Factors Determining the Performance of Indexing Systems: Volume 2
Test Environment
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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Co-ordination
Search Rules
Precision
Device
Document
19 elevance
Recall Exhaus -
Device tivity
1,1 1
2
3
1,2 1
2
I. 3
1,5
1,6
R P
25 9
35 5
38 4
25 8
1375
1
R P
28 2
44 1
44 1
28 2
50
1-3
R P R P R P 8
17 17 19 24
28 i0 30 15
33 101 33 14 28 23 2
17 1 19 23
30 I 31 15
3
1
2
3
1
2
3
1
2
3
50 j 39 4
I
39 31 3O 9
I
56 II 41 5
56 1I 43 4
39 1 27 4
56 1 41 2
56 1 44 2
44 1 32 4
56 1 42 2
56 1] 47 1
t
24
37 41 40 6
4441 45 5
1 35 L3 29 21
1 21 [OCRerr].3
I 33 t3
36 tl 33 15
25 14
38 1
4] 44 { 40 8
8 26 12
44 7
2
24 24
27 12
30 II
1-4
.......... o .......... , .....
I
R P
6 19 32
19 32
22 24
26 ii
29 11
..... i
R P[ R P
12 31 28 29
12 31 29 3O
15 29 33 24
18 15: 36 14
21 151 40 ii
i
R P
21 59
27 5'
[OCRerr]IGURE 2,10a
THE COMPOSITE TABLE, COORDINATION LEVEL 4+
R = RECALL RATIO, P = PRECISION RATIO
(Performance figures are expressed as percentages)