Mechanization of library procedures in the medium-sized medical library. XI. Two methods of providing selective dissemination of information to medical scientists.

The purpose of this study was to determine if a computerized commercial selective dissemination of information service could contribute to the services offered to the patrons of a specific medical library who were already participating in a manual selective dissemination of information service. The citations generated by the two services were contrasted on the basis of literature coverage, timeliness of retrieval, and relevancy of output. Eighty-four percent of the discrete citations retrieved were from 664 periodicals subscribed to by both services. Only 16 percent of the total of 1,387 discrete citations were produced by both services. The manual service was more timely; and, although it produced fewer citations, a higher percentage of these were relevant. Numerically, a total of 346 useful citations were recovered by the manual service and 379 from the commercial service. It appears, therefore, that a computerized commercial SDI service could contribute to the services offered to the medical scientists participating in a manual SDI service.