TEACHING WITH ANALOGIES - A CASE-STUDY IN GRADE-10 OPTICS

Analogies have long been tools of discovery in science and are often used as explanatory devices in the classroom. However, research has shown that analogies can engender alternative conceptions because some students visualize the analog in a different manner than the teacher and/or invalid analog-target transfers are left unchallenged. This case study describes one teacher's implementation of a modified version of Glynn's Teaching-With-Analogies (TWA) model with a Grade-10 optics class on refraction of light. The analogy likened a ray of light as it passes from air into glass to a pair of wheels that changed direction as they rolled obliquely from a hard onto a soft surface. The study indicates that a competent teacher can integrate this systematic approach into a teaching repertoire resulting in student conceptual understanding of the phenomena as expected at this level of science education. For analogies to be effective, it appears essential that the analogy be familiar to as many students as possible, that shared attributes be precisely identified by the teacher and/or students, and that the unshared attributes should be explicitly identified. The discussion concludes with recommendations for teaching and future research and discusses some limitations of this approach to analogical instruction.