Abstracts - Earli

investigated how different prior knowledge activation affects learning success in a hypertextenvironment. Subjects with two different levels of expertise (43 high-school and 45 physicsuniversity students) were randomly assigned to three conditions (1) labeling-existing-lines (2)creating-and labeling-lines and (3) a control group with no prior knowledge activation.Preliminary results confirm a positive effect of expertise, a positive effect of prior knowledgeactivation, and an interaction between expertise and the coherence of prior knowledge activationfor questions assessing the understanding of higher-order-structures.K 2431 August 2007 08:30 - 10:30Room: 1.71 PóczaSymposiumBuilding Dynamic Mental Models from Visualizations (II)Chair: Richard K. Lowe, Curtin University of Technology, AustraliaOrganiser: Wolfgang Schnotz, University of Koblenz-Landau, GermanyOrganiser: Richard Lowe, Curtin University of Technology, AustraliaDiscussant: Neil Schwartz, California State University Chico, USAInstruction frequently aims at the learner’s understanding of dynamic systems, which requires theindividual to construct a dynamic mental model of the system and to perform mental simulationsby ‘running’ the mental model in order to solve specific tasks. A frequent assumption hold bypractitioners is that the temporal characteristics of an external visual representation shouldcorrespond to those of the represented content. This would imply that static pictures should beused to display static content because they lead to the construction of a static mental model,whereas animated pictures should be used to display dynamic content because they lead to theconstruction of a dynamic mental model. A more detailed consideration reveals however that thisis not the case. Static pictures are not limited to supporting the construction of static mentalmodels, but can also be the basis for constructing dynamic mental models and dynamicvisualisations are not limited to supporting the construction of dynamic mental models but can alsolead to the construction of static mental models. This symposium will argue for a unified approachto dealing with visualizations with a special focus on constructing dynamic mental models fromvisualizations, regardless whether these visualizations are static or dynamic. It will analyze thenature of dynamic mental models in different domains using different methodological approaches,and it will focus on the question how dynamic perceptual schemata and prior knowledge aboutdynamic events can be used in the construction of dynamic mental models from external visualdisplays. Instead of the simple, but misleading research question, whether dynamic visualizationsare more effective than static ones or not for the construction of dynamic mental models, thesymposium will address the question, when (i.e. under which conditions) which kind ofvisualization will be more beneficial for the construction of dynamic mental models.– 641 –