Affiliation:
1. (Department of Statistics), London School of Economics and Political Science, Houghton Street, London WC2A 2AE, UK
Abstract
The relationship between mean control scores and mean experimental scores in 23 experiments on alignment illusions has been examined. Evidence is presented to show that, through the operation of the range effect, control scores are biased to a significant degree in the direction of experimental scores. The implications of this are considered, not only as regards the value of control scores in psychophysical studies, but also as further evidence of the dangers of within-subjects experimental designs when issues depend upon the values of extreme points in a range of values.
Subject
Artificial Intelligence,Sensory Systems,Experimental and Cognitive Psychology,Ophthalmology