The MEDLARS demand search quality control program.

Abstract

A Quality Control Unit was established at the National Library of Medicine to provide preventive quality control on a continuing basis for MEDLARS. This unit provided analyses of retrievals and made recommendations for improvements based upon these analyses. For the period January 1969 to June 1970, 21,000 MEDLARS searches were released in the United States. Appraisals were returned by 24.4% of the users. They reported that 55% of the citations retrieved were relevant and that 47% of the citations were new to them; 70.6% of the users reported recall of 50% or higher.