Abstracts - Earli

striking individual differences in how people interact with the external visualizations that arerelated to performance of the cross section task. Our results suggest that when using externalvisualizations the quality of visual information available to participants is more important thaninteractive control per se. Interactive computer visualizations can augment performance on spatialinference tasks, but that they do so only for a subset of individuals who can discover how to bestuse the additional information that they provide.Effects of modality and reflection in animated expert modelsPieter Wouters, Open University of the Netherlands, NetherlandsFred Paas, Open University of the Netherlands, NetherlandsJeroen van Merriënboer, Open University of the Netherlands, NetherlandsIn animated models, experts explicate how a problem is solved and why a particular method ischosen. When abstract cognitive processes or concepts are involved, dynamic visualizations (i.e.,animations) might be beneficial for novices. Cognitive load theory was used to investigate whetherreflection could help novices to engage in relevant learning activities. We argued that for complexexplanatory text, written explanations would facilitate the selection and organization of wordsbetter than spoken explanation and therefore yield more coherent mental representations uponwhich meaningful reflection is possible. Consequently, we hypothesized that learners with writtenexplanations would yield better transfer performance with reflection prompts, whereas reflectionprompts would have no effect with spoken explanations. The results confirmed the hypothesis withtransfer performance on the post-test. Implications for the design of animated models arediscussed.Using static pictures associated with dynamic visualizations to improve the learning of proceduraldocumentsAmael Arguel, University of Rennes 2, FranceEric Jamet, University of Rennes 2, FranceAnimations offer advantages to present temporal information that involves change over time. Butin numerous situations, static displays are as much beneficial and sometimes better (Betrancourt&Tversky, 2000). This fact could be explained by considering the lack of control for the learnerwhile watching animations, and also the transient nature of the animations themselves (Mayer &chandler, 2001; Betrancourt, 2005; Hasler, Kersten & Sweller, 2006). In our study, we test a newway to present dynamic visualizations in order to improve learning efficiency without usingcontrol possibilities from the learners. We used videos presenting first aid gestures underneathwhich still screenshots from the video itself were shown. We have manipulated the dynamism ofthe appearance of these pictures (i.e. static vs. dynamic) and the frequency of the pictures (i.e. thenumber of pictures shown). We argue that this kind of presentation could be efficient in terms oflearning, especially when the pictures are appearing dynamically near the video because of (1) thetransient negative aspect of animation that could be limited and (2) the fact that explicitly pointingout the important moments of a procedural event could improve the understanding of novicelearners (Zacks & Tversky, 2003). Our results are relevant to our hypothesis. We can observe aninteraction trend between the factors showing an increase of the dynamism effect when thefrequency of the pictures becomes higher.– 512 –