Hans Peter Luhn and Herbert M. Ohlman: Their roles in the origins of keyword-in-context/permutation automatic indexing

The invention of automatic indexing using a keyword-in-context approach has generally been attributed solely to Hans Peter Luhn of IBM. This article shows that credit for this invention belongs equally to Luhn and Herbert Ohlman of the System Development Corporation. It also traces the origins of title derivative automatic indexing, its development and implementation, and current status.