The often observed nonlinearity between magnitude estimations and category ratings has raised the question whether subjects can judge sensation differences as well as sensation ratios when instructed to do so. For brightness this will be shown to be the case; the rank order of difference judgments differs from the rank order of ratio judgments. Nonmetric analysis of these rankings yields a ratio scale for brightness perception that is (1) a power function of luminance (power: 0.13), (2) linearly related to direct category ratings, (3) nonlinearly related to direct magnitude estimations. Implications for the nonlinearity between magnitude estimations and category ratings are discussed.
|Title of host publication||Abstracts of te XXV International Congress of Psychology, July 19-24 1992, Brussels, Belgium|
|Publisher||Union Internationale de Psychology Scientifique|
|Number of pages||1|
|Publication status||Published - 1992|
|Name||International journal of psychology|