Service to an Interdisciplinary Need-group from Computerised Secondary Services

Abstract

The extent to which a specialised interdisciplinary need-group can assemble its reference base from computerised secondary services, and associated problems have been explored. The reference file of journal literature published in 1969, collected by the Biodeterioration Information Centre, was taken as typifying the reference requirement of a specialised need-group. Its coverage by Chemical Abstracts Condensates, Chemical Biological Activities, Chemical Titles, BA-Previews, MEDLARS, Food Science and Technology Abstracts and the services provided by the Institute for Scientific Information (ISI) was determined by item-by-item check. It was found that the best service covered 60% of the reference file, and that all services together covered almost 77%. 23% of the reference file was not covered by the secondary services examined, and inspection of this non-covered subset indicated that non-coverage could not be attributed to triviality or irrelevance of content. Profiles for machine search of the secondary services were compiled, based on comparison of the frequencies of occurrence of terms in the references composing the reference file with frequencies of occurrence of the same terms in the files to be searched, in order hopefully to produce the greatest number of relevant references at least cost per relevant reference retrieved. Searches were carried out on the ISI Base, CA-Condensates, Chemical Titles, BA-Previews and MEDLARS, and the results were assessed for relevance of retrieved references. There are indications that as terms are used in descending order of specificity, both the over all cost per relevant citation retrieved and the proportion of irrelevant items retrieved tend to increase. The non-availability of complete coverage from existing computerised secondary services and the cost and difficulty of extracting relevant references from them suggest that reliance on these services for the servicing of the reference requirements of interdisciplinary need-groups is not yet practicable.