EFFECTS OF EXPECTATION UNCERTAINTY AND SURPRISE ON QUALITY PERCEPTION FACTORS OF EXPECTATION EFFECT

In the user's perception of a product's qualities, the state of their sensory modality may shift from one state to another. For example, users see and then touch a product to perceive its texture. Between such state transitions, users have expectations regarding their subsequent states based on their experience of a current state event. Expectation effect is a psychological effect in which prior expectation changes posterior perception itself. The effect is a key factor to design user's emotions induced by expectation disconfirmation as well as designing a perceived quality based on prior expectations. Although experimental findings on the expectation effect exist in a variety of research disciplines, general and theoretical models of the effect have been largely neglected. The present authors previously found out the visual expectation effect on tactile perceptions of surface texture. The causes of the expectation effect, however, remain largely unexplored. To intentionally design the expectation effect, general and theoretical models that estimates conditions of the effect is needed. In this paper, we propose a theoretical model of the expectation effect using information theory and an affective expectation model (AEM). We hypothesize that Shannon's entropy of the prior subjective probability distributions of posterior experience determines the occurrence of the expectation effect and that the amount of information gained after experiencing a posterior event is positively correlated with the intensity of the expectation effect We further hypothesize that a conscious level of expectation discrepancy distinguishes between two types of expectation effect, namely, assimilation and contrast. To verify these hypotheses, we conducted an experiment in which participants responded to the tactile qualities of surface texture. In the experiment, we extracted the visual expectation effect on tactile roughness during a sensory modality transition from vision to touch and analyzed the causes of the effect based on our hypotheses. The experimental results indicated the appropriateness of the proposed model of the expectation effect.