A Cognitive Framework for Reasoning with Scientific Models

ion and re-representation. COMPARING ANALOGIES AND MODELS The terms model and analog are often used interchangeably by both scientists and educators (Hesse, 1966, 2000; Duit, 1991). Comparing analogs and models based on the preceding review of the characteristics of each suggests that this interchangeability is valid when analogies are based on relational characteristics. The term "representation" is used with respect to models and can be applied to analogs as well. Analogs can be individuals’ representations as in mental models (Johnson-Laird, 2006) or a more public form of representations as in those presented in textbooks. The term “elements” refers to concepts, objects, systems, data, processes or events in both analogies and models. The only distinction between the definitions is the implication that scientific models are accepted by a community of experts whereas analogies may be less rigorously evaluated. Analogs based on mere similarity and relational analogs that are not accepted by a community of scientists are not equivalent to models, but relational analogs that are accepted by the community are equivalent to scientific models. Comparisons can be drawn between Holyoak’s (2005) model of reasoning by analogy and model-based reasoning in science (Figure 1). The following discussion of the cognitive processes will proceed step-wise but it is not intended to imply that people follow a step-wise path TABLE 3. ANALOGY AND OTHER TYPES OF SIMILARITY1 TYPE OF SIMILARITY DESCRIPTION GEOLOGICAL EXAMPLE REFERENCE Involves a target that is to be explained or described, and a source that is already understood; can be based on relational matches and/or object matches between source and target. Granite and gabrro could be categorized as analogical based on shared relations (igneous, intrusive). Hummel and Holyoak, 2003 Based on abstracted characteristics; is useful for categorization and for generating inferences about instantiations. Sedimentology textbooks present prototypes and exemplars of sedimentary deposits formed in a variety of environment (e.g., beach, fluvial) that students are expected to be able to compare to the target. Osherson and Smith, 1981 Exemplar of a category; otherwise similar in function to prototype The type section of a formation. Stoman and Ripps, 1989 Mere similarity (non-relational analog) Similar in attributes but not relationally similar. Granite and granite paragneiss have obvious similar appearance and could be categorized as mere similarity. Gentner and Markman, 1997 Literal similarity Similar in both attributes and relationally similar. Granite and granodiorite share both attributes and relations (they are both igneous) and therefore could be characterized as literally similar. Gentner and Markman, 1997 Metaphor Linguistically embedded analogs. The phrase heat flow refers back to the now defunct model of heat as a fluid. Lakoff and Johnson, 1980 Relational Analog (relational similarity)