<DOC>
<DOCNO> IRS13 </DOCNO>
<TITLE> Scientific Report No. IRS-13 Information Storage and Retrieval </TITLE>
<SUBTITLE> Thesaurus, Phrase and Hierarchy Dictionaries </SUBTITLE>
<TYPE> chapter </TYPE>
<PAGE CHAPTER="7" NUMBER="25">
<AUTHOR1> E. M. Keen </AUTHOR1>
<PUBLISHER> Harvard University </PUBLISHER>
<EDITOR1> Gerard Salton </EDITOR1>
<COPYRIGHT MTH="December" DAY="" YEAR="1967" BY="National Science Foundation">
Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government.
</COPYRIGHT>
<BODY>
Stem(s) versus Thesaurus(t)
Input, Matching Function Precision at Recall Normalized
No. Collection and Thesaurus Type .2 .5 .8 Rec. Pre.
3 Title, Cosine Numeric, Thes-2 T T T T
4 IRE-3 Title, Cosine Numeric, Thes-3 T []T T [[OCRerr]j
5 34 Abstract, Cosine Logical, r£hes[OCRerr]3 T T T T T
6 Requests Abstract, Overlap Logical, Thes-2 S S T T S
7 Abstract, Overlap Logical, Thes-3 T T T T T
11 Cran-l Title, Cosine Numeric, Thes-3 S S flT T T
14 42 Abstract, Cosine Logical, Thes-3 T flT T []T
15 Requests Abstract, Overlap Logical, Thes-3 T T T
17 Text, Cosine Numeric, Thes-SAl S S S
19 Abstract, Cosine Numeric, Thes-SAl S S S S S
The difference of one dictionary merit over the other is smaller than 0.05
alone appears, and larger than 0.05 when letters [OCRerr]re circled.
when a letter
Table Summarizing 18 Precision Versus Recall Plots not Presented, Comparing
Stem and Thesaurus Dictionaries on Three Collections.
Fig. 17
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