Infrared file searching programs must try to achieve high relevance while allowing for errors between the coded standard data and the unknown. A scoring system has been devised so that individual searches can be quantitatively evaluated; this also allows the overall performance of the search algorithm to be calculated. Several searching programs for the ASTM ir data file are compared using a test group of 138 unknown spectra selected at random from the literature. Search costs and a cost/performance ratio are also calculated for each system.
