MEDLINE at BRS, DIALOG, and NLM: is there a choice?

Since May 1981, MEDLINE has been offered by three vendors: Bibliographic Retrieval Services, DIALOG, and the National Library of Medicine. Although the contents of these MEDLINE files are basically the same, they have major differences: on-line versus off-line coverage, costs, hours, software capabilities, and bibliographic variations. MEDLINE searchers need to know about the important differences among these three files whether or not they have direct access to them. Ideally, a searcher should have access to all three MEDLINEs. However, staying up to date on the basics of comparative MEDLINE searching should be the responsibility of each MEDLINE searcher. A broad-based decision about a vendor must consider the characteristics of each MEDLINE file and of each search request.