Using lecture demonstrations to promote the refinement of concepts: the case of teaching solvent miscibility
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Guy
Ashkenazi
*a and
Gabriela C.
Weaver
b
aDepartment of Science Teaching, The Hebrew University of Jerusalem, Israel 91904. E-mail: guy@fh.huji.ac.il
bDepartment of Chemistry, Purdue University, West Lafayette, IN 47907
Abstract
Novices often lack the descriptive knowledge of phenomena that is the basis for an expert’s interpretation of scientific concepts. Such lack of knowledge may lead to poor conceptual understanding, and misinterpretation of these concepts. Lecture demonstrations can provide essential experiences that serve as a context for discussion of over-generalized or over-simplified concepts. The design of such demonstrations starts from surveying the limited knowledge base of the student, followed by exploration of the richness of relevant contexts of the expert, and identifying key instances that can serve as meaningful discussion topics. An example of the design of a demonstration set for teaching solvent miscibility and its relation to intermolecular interactions is given, followed by results of its application in two different presentation modes: confrontation (aims at generating a conflict with existing conceptions) and refinement (aims at promoting differentiation and contextualization of scientific concepts). The students’ involvement in peer discussion, associated with these demonstrations, is evaluated by considering the distribution of students’ predictions. [Chem. Educ. Res. Pract., 2007, 8 (2), 186-196]