Norm and context: Dichotomization of stimuli and response scales influences context effects in absolute judgments.

Range effects, which are contextual effects on perceptual judgments, can be subject to a limitation when a dichotomous pre-established norm. is availa ble. These limitations, initially observed by Marsh and Parducci (1978), co nsist of a neutral-point anchoring and of a symmetrization of the subjectiv e range. Four experiments show that these limitations 1 / do not cancel the usual range effects, 2 / can be observed with various stimuli, and 3 / can be explained by various processes linked to response scales or to stimuli. This diversity can guide the analysis of similar effects that occur in eve ryday situations.