Computer-aided estimation of psychophysical thresholds by Wetherill tracking

Abstract

We describe a microcomputer implementation of an efficient procedure to obtain psycho-physical thresholds at any of three response-probability levels, by Wetherill tracking. The procedure yields reliable 50% thresholds (average coefficient of variation=5.1%) based on about 30 responses. Thresholds obtained in this way correlate highly with constant stimulus measurements requiring six times as many responses. Computer-assisted Wetherill tracking should find wide application in psychophysical screening tests. © 1979 Psychonomic Society, Inc.