Identifying effective instructional approaches that stimulate students' critical thinking (CT) has been the focus of a large body of empirical research. However, there is little agreement on the instructional principles and procedures that are theoretically sound and empirically valid to developing both domain-specific and domain-general CT…

This study aimed at experimentally investigating the moderating role of instructional conceptions on the effectiveness of powerful learning environments (PLE) designed in line with the four-component instructional design model (4C/ID-model). The study also investigated the influence of learning in a 4C/ID PLE on students' instructional…

The aims of the present studies were to test the generalizability of the modality and dialogue effect to open learning environments, previously found by Moreno and Mayer (e.g., Moreno, Mayer & Lester, 2001) with an agent providing metacognitive support. As an extension, the agent's continuous presence effect on learning was also tested. Three…