A technique for the evaluation of a commercial information service and some preliminary results from the drugdoc service of the excerpta medica foundation

The selectivity, timeliness and quality of indexing of a commercial service may be assessed by comparing the journal articles chosen by an organization as relevant to its interests, with those subsequently reported by the service. These aspects were evaluated with respect to Drugdoc which scans over 3400 biomedical journals. The results showed that the selection criteria laid down by Drugdoc are strictly adhered to; the mean time of alerting of an article was 11.3 weeks after receipt of the journal at Wellcome and all articles from a particular journal issue were reported by Drugdoc on average within 13.6 weeks. Indexing was examined in detail and on average 8.1 primary thesaurus-controlled indexing terms were assigned per article. Pilot studies were also run on S.D.I. profiles compiled from the Drugdoc Thesaurus.