Can We Teach Reasoning? Should We?

4 April 1997 • Journal of Chemical Education 365. Chemical Education Today conditional logic. It appears that reasoning can be taught, but we are no...
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Chemical Education Today

Editorial: Can We Teach Reasoning? Should We? A reader’s reaction to what I wrote here in December conditional logic. It appears that reasoning can be taught, led me to a very interesting article in Science, where Nisbett but we are not doing it! (Of course the data might also imet al. report psychological studies that suggest that “…even ply that our students’ abilities are already at such a high brief formal training in inferential rules may enhance their level that they cannot be improved, and we could argue that use for reasoning about everyday life events” (1). But the authe types of reasoning ability the psychologists were lookthors also quote data that imply that chemistry graduate ing for are not needed by chemistry students.) programs are not very effective in helping students develop It is certainly true that in most undergraduate chemistheir abilities to apply statistical reasoning and logical reatry curricula students are much more often confronted with soning to unfamiliar problems. problems that have definite, deterministic answers than they The idea that formal study of abstract systems of rules are with problems that may have several answers or no andevelops habits of mind that are useful in reasoning about swer at all. The chief exception to this is undergraduate reconcrete problems has been search, which does involve around for a long time. Plato, for students in questions to example, argued that study of …students are much more often confronted which their experimental arithmetic and geometry was efanswer is not going to be fective in improving reasoning, with problems that have definite, deterministic checked against the back of and that improving the arithmeti- answers than they are with problems that may the book. Since undergraducal and geometrical skills of its ate research has obvious leaders would serve a state well. have several answers or no answer at all. benefits in the maturation of Other formal systems, grammar, young chemists, wouldn’t it logic, and languages, were added to arithmetic and geommake sense to try to make some of the same benefits availetry, resulting in the classical college curriculum of the nineable to students in nonresearch courses? But how? teenth century—a curriculum that did not include chemisNisbett et al. provide some ideas for us to try. In some try or other natural sciences. cases using examples alone, or teaching general logical The incorporation of science into the curriculum that rules alone, will suffice. We are at that stage in the textbegan in the late nineteenth and early twentieth centuries books and teaching methods of many of our undergraduate was based to some extent on experimental evidence that courses now. Books are full of very specific examples of how cast doubt on Plato’s idea that formal training in reasoning to solve relatively simple problems. Indeed, some students would carry over into all aspects of a person’s intellectual don’t bother to read the book at all, because concentrating and practical life. Thorndike, on the basis of empirical reon the examples will make them successful on our tests. I search on transfer of training effects, argued that there are think that there are many cases in chemistry teaching no general inferential rules that apply to all disciplines (2). where we need to go much farther than the excellent exInstead there are highly specific empirical rules that deal amples we already have, and Nisbett et al. reinforce that with concrete events and apply to other events only to the belief. More important than either a formal discipline of extent that the two have identical elements in common. logical rules or examples of applying those rules is the comPiaget agreed with Plato that people use inferential rules, bination of the two: abstract training closely coupled with but argued that these cannot be taught to any significant concrete, real-world examples (very different from the textextent (3). Every individual develops such rules in the norbook examples just mentioned) of how to apply the abstract mal course of maturation, but instruction cannot alter that ideas in a variety of situations. development. Both of these positions argue against the clasI ran the Nisbett paper by a psychologist friend of mine, sical, one-size-fits-all curriculum. and he took it one step farther. The really hard trick, after Nisbett et al. take an alternative view that is closer to knowing abstract rules and being familiar with examples Plato’s: people do use inferential rules, and such rules can of applying them, is to know which set of abstract rules will be taught, sometimes by abstract means. However, Nisbett work in a new situation. (Or, from a more disciplineet al. argue that the rule systems people use naturally (and chauvinistic perspective, to know to which kinds of new that can be taught) are pragmatic and are induced in the situations chemistry’s abstract rules will apply. Fortunately process of solving recurrent everyday problems. With respect there are a great many.) We need to present students with to training in statistical reasoning they found that either a broad range of situations where they can practice skills teaching statistical rules or teaching by having students of choosing and applying abstract sets of rules to unfamilsolve example problems would work. With respect to trainiar problems. Concentrating too much on the standard, relaing in conditional logic, they found that neither abstract logitively simple “problems” in most textbooks and examinacal training nor showing subjects how to use rules to solve tions is not enough. So let’s work to go beyond that in problems would work alone, but when these two approaches creative and effective ways! were used simultaneously, students learned. To me the most interesting aspect of the Nisbett paper is also the most disturbing. Chemistry was one of four disciplines within which they studied the effect of two years of Literature Cited graduate work, both on statistical and methodological rea1. Nisbett, R. E.; Fong, G. T.; Lehman, D. R.; Cheng, P. W. “Teaching soning and on applying conditional logic to solve problems. Reasoning”; Science 1987, 238, 625–631. Two years of graduate study did not significantly improve 2. Thorndike, E. The Psychology of Learning; Mason-Henry: New chemistry students’ abilities in either area, although it did York, 1913. improve the abilities of medical students and psychology 3. Brainerd, C. Piaget’s Theory of Intelligence; Prentice-Hall: students in both areas and the abilities of law students in Englewood Cliffs, NJ, 1978.

Vol. 74 No. 4 April 1997 • Journal of Chemical Education