The way of the innovator: notes toward a prehistory of MEDLARS.

The concept of MEDLARS as a publication/retrieval system was the product of several forces operating during the fifteen years prior to 1961. These included the overriding imperative of medical index publication, the Welch Medical Indexing Research Project, a drive to master the theory of medical subject headings, the innovative impact of coordinate indexing, and the confidence produced by the success of the Index Mechanization Project. By virtue of this experience, MEDLARS became a prime example of a well-understood enterprise seeking a computer application, a circumstance which augured of its success.