On the role of the laboratory in learning chemistry
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Chemistry is a laboratory science; hence, no instruction in chemistry would be complete without some laboratory component. But in a discipline as wide-reaching as chemistry is, the natural questions of what should be taught and how it should be taught are not trivial. Indeed, these questions have been on the minds of chemical educators for many years. Current instructional models in chemistry laboratories can be grouped under several broad descriptions. Expository laboratories are intended to illustrate important chemical principles. While these laboratories offer the benefit of reinforcing lecturebased instruction, students often know the outcome of such experiments in advance, and this model of instruction does not accurately depict the process of accumulating scientific knowledge. To address this apparent shortcoming, inquiry models have been developed. Discovery (or, Guided inquiry) laboratories focus primarily on the scientific method, providing students with some instruction towards addressing the problem at hand, but also requiring students to develop some decision-making processes of their own. Inquiry (or, Open inquiry) laboratories provide less assistance to the students, effectively obligating them to develop complete procedures for themselves. The difficulty with these models is that content almost becomes irrelevant; the focus is on the process of obtaining scientific information. Even then, these models still do not accurately reflect the nature of scientific work; scientific inquiry always begins from some knowledge base, which these models do not presuppose. Feeling that none of these models adequately addresses the needs of chemistry students, at The University of Texas at Austin we have developed a new General Chemistry laboratory course based on the idea of introducing students to chemical research. As a model, we employed Cognitive Apprenticeship theory, which is based on traditional craft apprenticeships but is adapted to cognitive domains. It appears to be suitable as a model for laboratory instruction because it assumes that content matters, that the sequence for that content is important, and interaction between the instructor/ mentor and the student/ apprentice is essential. Both the immediate and longitudinal effects of the research-based course on introductory students are compared to those of a standard Expository laboratory course.