Motivation,ability, and exam performance: Tests of hypotheses of cultural difference and task difficulty

In a series of three experiments, prediction of exam performance from information about motivation and ability of students was studied. The factorial plot of the Motivation × Ability effect on predicted performance always yielded the parallelism pattern with subjects from both the student and nonstudent populations. Results agreed with the hypothesis of cultural difference between America and India. Manipulation of difficulty of exam did not alter the parallelism pattern, contrary to the specification of the hypothesis of task difficulty. Difficulty of exam affected only the origin of the response scale. Implications of results were discussed for the two tested hypotheses as well as for a new hypothesis of nature of task.     

Explaining Context Effects on Choice Using a Model of Comparative Judgment

Context effects refer to the shifts in shares when another alternative is introduced in the choice set. The alternative can be asymmetrically dominated, asymmetrically dominating, totally dominated, or totally dominating. We developed a theoretically derived model based on the shifts in attribute valuation as a potential explanation for all context effects. First, the model is tested using data from previously published studies. As predicted, the results showed a high correlation between shifts in valuation and changes in the choice shares. The model is also tested using 2 studies that extend the design of the choice sets to include better alternatives in a search context and the removal of an alternative. The strong relation justifies the case for comparative valuation as an underlying mechanism for context effects. Assuming this valuation, the article illustrates how the framework can be used to develop new product strategies taking into account the values of the unchosen alternatives.     

Predictability and Variability of a Dynamic Environment Impact Affordance Judgments

Abstract

A crucial component of locomotion and mobility is the successful navigation of apertures (e.g., doorways, lanes, corridors). While much research has studied perceptions of action capabilities in a static environment, far less work has considered how action capabilities change in a dynamic environment, particularly when the environment moves in unpredictable ways. The current experiment assessed actors’ perceptions of aperture passability for a dynamically moving gap. In an immersive virtual environment, participants were seated in a wheelchair rolling toward a sliding door while the door oscillated to various widths. The patterns of oscillation were manipulated in terms of their amplitude (sequence standard deviation), predictability (sequence sample entropy), and base width (sequence mean) in a within-participants design. Participants gave judgments of passability within a temporal occlusion paradigm. Results showed that both the amplitude and predictability of the oscillating door impacted the reliability of passability judgments. We suggest that these variables act to alter the salience of optical constraints (e.g., attractors and repellors) within a dynamical systems framework.