Learning with Diagrams: Effects on Inferences and the Integration of Information

Students studied materials about the human heart and circulatory system using either (a) text only, (b) text with simple diagrams, or (c) text with detailed diagrams. During learning, students self-explained [1] the materials. Explanations were transcribed, separated into propositions, and analyzed according to the type of learning process they represented. Results demonstrated that diagrams promoted inference generation but did not affect other learning processes (such as elaboration or comprehension monitoring). However, only simple diagrams promoted generation of inferences that integrated domain information. Results indicate that diagrams may be useful because they guide the learner to engage in the cognitive processes required for deep understanding. 1 Rationale and Experimental Approach In recent years there has been growing interest and enthusiasm regarding the addition of visual resources to educational materials. The overall conclusion of previous research on text with pictures is that the addition of visual material improves students' memories and understanding [2]. In addition, Mayer and his colleagues have identified a number of principles that describe situations in which multimedia materials are most effective [3]. Although such principles are useful in identifying conditions that can maximize multimedia benefits, there is little evidence as to why diagrams improve memory and learning. The goals of this research were to determine: (a) if the comprehension processes of learners using text and diagrams were different from learners using text only, and (b) whether diagram complexity would influence comprehension processes. A simple text about the heart and circulatory system was used alone or in conjunction with a series of diagrams from one of two types: diagrams that were simplified to emphasize the functional aspects of the heart (see Figure 1a), or more detailed diagrams that depicted the correct anatomy of the heart in addition to its functional aspects (see Figure 1b). During learning, students self-explained the materials [1] and the resulting verbal protocols were separated into a series of complex propositions [4]. Two raters scored propositions as: paraphrases (statements that reflected information from the current * Kirsten Butcher has moved to a joint appointment at the National Center for Atmospheric Research and the University Corporation for Atmospheric Research: UCAR Foothills Lab 4; Room #3304; P.O. Box 3000; Boulder, CO 80307-3000. [email protected] A. Blackwell et al. (Eds.): Diagrams 2004, LNAI 2980, pp. 337-340, 2004. © Springer-Verlag Berlin Heidelberg 2004 338 Kirsten R. Butcher and Walter Kintsch materials), elaborations (connections to prior knowledge), monitoring statements (utterances that demonstrated comprehension monitoring), or self-explanation inferences (statements that went beyond current materials or that integrated current and previous material). Because self-explanation inferences included multiple types of inferences, they also were separated into subcategories: path inferences (inferences that concerned the path of blood through the heart and circulatory system), nonpath inferences (inferences concerning content other than the path of blood), and integration inferences (inferences that connected current and previous information; these included path or nonpath inferences that integrated information). Interrater reliability ranged between .70 and .99 (M = .88). Additional work assessed students' mental models of the domain and the relationship between inference generation and mental model development [5]. Students drew and explained the heart and circulatory system before and after learning; these materials allowed mental model assessment and were scored for accuracy according to criteria from Chi et al. [1]. Fig. 1. (1a) A simple diagram emphasizing functional relations. (1b) A detailed diagram preserving anatomical accuracy