Abstracts - Earli

is having learners externalize their knowledge (e.g. by creating concept maps, summaries, buildingmodels, etc.). In the case of probability, a sub-domain of mathematics, it has been found that in theprocess of externalizing knowledge, learners tend to use self-invented representations (rangingfrom textual statements to conventional numerical representations to hybrid forms) rather thanstandard notations, because self-invented representations apparently are more meaningful to thelearner. The aim of the current study was to determine (1) whether the expression of knowledgefacilitates the construction of mathematical knowledge in probability instruction, and (2) whetherthe format (graphical, mathematical, or textual) in which the learners express their knowledgeaffects learning outcomes. It was found that the expression of knowledge by learners is related toenhanced levels of situational knowledge and overall knowledge. Second, the format in which thelearners express their knowledge does not influence either the quality of the domainrepresentations or the learning outcomes. However, the format does affect the perceivedaffordances of the representational format (graphical, mathematical, or textual). In case of agraphical or textual format, about half of the learners were able to create a domain representation,whereas in the case of a mathematical format, less than 20% of the learners were able to create adomain representation.How to optimize learning from animated expert models?Pieter Wouters, Open University of the Netherlands, NetherlandsFred Paas, Open University of the Netherlands, NetherlandsJeroen van Merriënboer, Open University of the Netherlands, NetherlandsIn three studies we investigated how learning from animated expert models in the domain ofprobability calculation can be optimized. In animated expert models an expert solves a problemand explains how and why this is done in this particular way. Cognitive load theory contends thatthese models should be designed in such a way that learners prevent ineffective cognitive load andengage in relevant learning activities that impose effective cognitive load. Study 1 investigatedguidelines to reduce ineffective cognitive load and revealed that learner-paced spoken continuousanimated models led to better near transfer performance than spoken segmented animated models,whereas with written explanatory text learner-paced continuous animated models led to better fartransfer performance than segmented animated models. Study 2 and 3 investigated guidelines thathave learners engage in relevant learning activities. In Study 2 we argued that reflection promptswould stimulate learners to be cognitively active and integrate new information with their priorknowledge. The results showed that reflection prompts were effective with written explanatorytexts, but not with spoken explanatory texts. Study 3 investigated whether alternating betweenobserving models and practicing would ameliorate learning. We argued that observing andpracticing yield different ways of processing information and that alternating between these twoinstructional techniques would yield enriched schemas. Data of this study will be available inFebruary 2007. In the presentation the theoretical (e.g., what does this mean for the modalityeffect) and practical implications of these studies will be discussed.Supporting navigational and representational choices in hypermedia learning environmentsMaria Opfermann, Knowledge Media Research Center, GermanyPeter Gerjets, Knowledge Media Research Center, GermanyKatharina Scheiter, University of Tübingen, GermanyWhen learning with hypermedia environments, learners are provided with a high degree of learnercontrol, which, if used in an appropriate way, enables them to learn in an active, constructive, selfregulatedand adaptive way. However, our own prior studies showed that learners do not– 591 –