Abstract
An experiment in which three groups of 10 Ss made absolute (identity) judgements of lifted weights under no anchor (NA), heavy anchor (HA), and light anchor (LA) conditions is described. No contrast effect induced by LA could be demonstrated but HA induced a significant contrast effect. It is concluded after an examination of response uncertainty conditional upon the individual stimuli, response speed scores and confidence scores that the primary effect of HA was to reduce the relative discriminability of series stimuli nearest HA and to increase the relative discriminability of those stimuli furthest from HA.