SDC experiences with large data bases.

SDC operates a large-data-base system that permits users all over the United States and in several foreign countries to search very large bibliographic files interactively, by means of a terminal and telephone connection. Developing extensive use of such systems requires not only technical considerations--such as proper selection and handling of data base elements--but also a massive educational effort, to help provide the large user community necessary to share the sizable costs of data base acquisition, file development, and storage. The growing acceptance of on-line retrieval services attests to the success of that effort, as well as to their inherent cost-effectiveness.