Representation for Problem Solving

Bodner, G. and Domin, D. (1995). The role of representations in problem solving in chemistry Toward a cognitive science perspective for scientific problem solving. A Monograph of the National Association for Research in Science Teaching, pp.245-263. Columbus, OH NARST. 

Embrey, D. E., Humphreys, P. (1985). Support for Decision-Making and Problem-Solving in Abnormal Conditions in Nuclear Power Plants. In L. B. Methlie R. H. Sprague (Eds.), Knowledge Representation for Decision Support Systems. Amsterdam North Holland. 

This new three-column format for solutions is designed to enrich the problem-solving experience by helping students to connect the calculation to chemistry concepts and principles, using macroscopic, molecular, and graphical representations. 

This diagram may appear trivial to the expert chemist but for a novice it contains much information about the chemical reaction at both the sub-micro and symbolic levels presented in multiple representational formats. Unless teachers are explicit in their use of these representations it is umealistic to assume that students would develop the same ability to choose an appropriate representation for a given process. It is possible that students can use and understand the representations without being able to see how they are related. Several authors (Hinton and Nakhleh, 1999 Kozma and Russell, 1997 Nurrenbem and Pickering, 1987) suggest that students are made aware of all three levels of representations and given opportunities to use them in solving problems. 

So far we have seen that if we begin with the Boltzmann superposition integral and include in that expression a mathematical representation for the stress or strain we apply, it is possible to derive a relationship between the instrumental response and the properties of the material. For an oscillating strain the problem can be solved either using complex number theory or simple trigonometric functions for the deformation applied. Suppose we apply a strain described by a sine wave ... 

An example of a problem solving tree for the synthesis of Darvon appears in Figure 3. The tree contains both AND nodes and OR nodes (7). The AND branches, connected by double arcs, indicate that both compounds are required to make the compound above them. The OR branches (there are three OR paths to make compound II) indicate different routes for making the compound. The terminal nodes corresponding to starting materials are enclosed in boxes. At present, a branch is terminated when the number of clauses in the clause list, the internal representation of the goal, is less than or equal to six or the clause list matches the clause list of a starting material molecule. 

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