Abstracts - Earli

Understanding dynamic mental models from learners’ visualizationsBarbara Tversky, Columbia Teachers College/Stanford University, USAResa Kelly, San Jose State University, USAOswaldo Garcia, San Francisco State University, USAOne reason that animated graphics are not more effective for teaching processes that occur in timeis that people think about such events as sequences of discrete steps rather than as continuousprocesses. This suggests that knowing the steps of complex processes should aid in the design ofeffective visualizations. Asking beginning learners and experts to generate their own visualizationsas well as verbal explanations provides clues to the steps as well as to visual devices. Twoprojects, one in meteorology and the other in chemistry, will illustrate the technique and it’soutcomes.Learning about dynamic systems by drawing for yourself and for othersShaaron Ainsworth, University of Nottingham, United KingdomJosie Galpin, University of Nottingham, United KingdomSusannah Musgrove, University of Nottingham, United KingdomThe construction of graphical representations such as diagrams has been found to be a successfullearning strategy in a variety of domains including dynamic mental model development. Thisinvestigation explored whether it was beneficial to construct a diagram for oneself or for anotherperson when learning about the cardio-vascular system. It also explored if individual differences inspatial ability mediated this effect. Forty 18-22 yr olds studied text passages about the humancirculatory system and then constructed diagrams containing information from these passages;twenty constructed diagrams under instructions to draw them to aid their own learning and twentyconstructed the diagrams with the instructions to draw them for another (low knowledge) person.Results showed that subjects improved significantly from pre-test to post-test on measures offactual knowledge but that this improvement was equal in both conditions. Measures of mentalmodel construction given at post-test also did not relate to drawing condition. However, drawingfor others led to diagrams that were judged as significantly clearer, as containing more of thepresented text, and which used more words. Furthermore, those with high spatial ability did notlearn more than those with low spatial ability nor did it influence the drawings that studentsconstructed. Finally, it was found that the quality of drawings was related to what students’ learnt– those students who translated more written text gained greater factual knowledge and thosestudents who drew more concrete diagrams developed deeper mental models (see Figure 1).Why situation models are dynamic ? Some theoretical, empirical and pedagogical argumentsIsabelle Tapiero, University of Lyon 2, FranceCurrent theories of text comprehension assume multi-level representations of a text and its content(Kintsch, 1988; Kintsch & van Dijk, 1978; van Dijk & Kintsch, 1983). Two levels that are usuallydistinguished are the semantic and the situational level (Fletcher & Chrysler, 1990; Tapiero, 1991).The semantic or textbase level includes both local and global processing, microstructure as well asmacrostructure. Microprocessing involves the construction of a locally coherent propositionalnetwork (including referential, temporal and causal relations) called the textbase. The globalstructure of the text, or macrostructure, accounts for what we call the gist of a text. But,understanding a text requires representing what it is about (e.g., relations between the local andglobal facts to which the text refers) and goes beyond the semantic level of representation.Whereas the microstructure and macrostructure remain close to the textual representation, building– 642 –