MEDLARS operating experience at the University of Colorado.

For a six-month period in 1965 the University of Colorado Medical Center Library conducted a demonstration project in which MEDLARS tapes received from the National Library of Medicine were searched on a Honeywell 800 computer located in Denver. Eighty-seven search requests were received from members of the UCMC staff during this period and successfully run. The average relevance and recall ratios were each in the neighborhood of 80 percent. Cost figures are given; it is calculated that an average search through two years' tapes costs about $200. The concept of the "search-month" is introduced, and it is shown that the average machine time per search-month will vary from 0.67 to 2 minutes. It is concluded that the technical and economic feasibility of decentralized search centers using a centrally prepared input has been demonstrated. Data are presented on the basis of which the performance of the system may be judged.