Design, Implementation and Evaluation of PsyWeb, a Learning Environment in a Problem Based Learning Curriculum.

In this article we describe the design and implementation of PsyWeb, a rich learning environment for the new problem based study in Psychology at Erasmus University Rotterdam Experiences are reported for the first five (of eight) courses of the first year of the new study. Students opinions have been collected as part of a survey at the end of each course. Results indicate that students are positive about PsyWeb. The overall appreciation shows a slight increase over time. Starting with the second course, usage of PsyWeb has been logged. Usage has been quantified in terms of the number of unique IP-addresses per day. Using this measure we assume that PsyWeb has a student reach between 25% and 100% per day. Usage shows a slight increase over the courses. The implementation of a series of additions to PsyWeb has been planned for the next year

Concavities as basic features in visual search: Evidence from search asymmetries

Item does not contain fulltextConcave cusps and negative curvature minima play an important role in many theories of visual shape perception. Cusps and minima are taken to be part boundaries, used to segment an object into parts. Because of their important role in determining object structure and because there is some evidence that object structure is processed in parallel, it might be expected that concave cusps and negative curvature minima are processed preferentially. We tested this conjecture in several visual search experiments. Visual search for a target with a concave cusp amongst totally convex distractors yields nearly flat slopes (<10 msec/item) for both present and absent trials. Reversing the roles of target and distractor results in inefficient search. The same asymmetry is found when the concave cusp is replaced by other types of concavity. We conclude therefore that concavities can serve as basic features in visual search experiments. This conclusion implies that the unit of selection in a visual search task is an object instead of a location

Clinical case processing by medical experts and subexperts

Medical specialists, diagnosing cases within their domain of expertise, do not rely on intentional causal reasoning, in which they use explicit principles or rules of their domain. Rather, their reasoning has become an automatic process using schema-based knowledge. However, the difference between diagnoses made by medical specialists and diagnoses made by nonspecialists (i.e., subexperts) is unclear. In the present study, cardiologists (the experts), pulmonologists (the subexperts), and advanced medical students evaluated two clinical cases within the domain of cardiology. The cases were divided into four components (i.e., patient's history, physical examination, laboratory data, and additional findings) that were sequentially presented. The task was to study, diagnose, and recall the segmented clinical case description. It was expected that the subexperts and students, as a result of their lack of specific expertise, would focus on different case components than the experts would. However, results indicated that the main difference between experts and subexperts (and to a lesser extent, students) was not a difference in emphasis on case components, but the speed and accuracy of processing these case component

Clinical case processing by medical experts and subexperts

Medical specialists, diagnosing cases within their domain of expertise, do not rely on intentional causal reasoning, in which they use explicit principles or rules of their domain. Rather, their reasoning has become an automatic process using schema-based knowledge. However, the difference between diagnoses made by medical specialists and diagnoses made by nonspecialists (i.e., subexperts) is unclear. In the present study, cardiologists (the experts), pulmonologists (the subexperts), and advanced medical students evaluated two clinical cases within the domain of cardiology. The cases were divided into four components (i.e., patient's history, physical examination, laboratory data, and additional findings) that were sequentially presented. The task was to study, diagnose, and recall the segmented clinical case description. It was expected that the subexperts and students, as a result of their lack of specific expertise, would focus on different case components than the experts would. However, results indicated that the main difference between experts and subexperts (and to a lesser extent, students) was not a difference in emphasis on case components, but the speed and accuracy of processing these case component