Xu, H.; Lancaster, F.W.: Redundancy and uniqueness of subject access points in online catalogs (1998)
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- Abstract
- Reports results of an analysis of 205 randomly selected records from the OCLC OLUC, to test the assumption that online catalogues have greatly improved subject searching capabilities, over card catalogues, by making other fields in the records searchable as subject access points (SAPs). Results showed considerable overlap (duplication) among the SAPs provided by the title, subject heading and classification number fields. On average, little more than 4 unique, unduplicated access points were found per record. Where title and classification number fields do add some access points not provided by subject headings, the increase is less than many librarians might be expected. Suggests that OPACs might outperform catalogues more in precision than in recall by allowing greater discrimination in searching; terms from different fields may be combined; titles offer greater specifity; searches can be limited by date, language or other criteria
