Abstract
Two matching methods with one and two variable stimuli respectively have been used in some earlier experiments investigating a brightness paradox defined by a higher brightness in one area than in an adjacent area having a slightly higher luminance. The inter- and intra- personal variation was lower when using two variable stimuli. The aim of the present study was to compare these matching methods and an estimation method(consistent sum)in studying the effect of inducing luminance on the size of the brightness paradox.