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

Analogies have long been tools of discovery in science and are often u sed as explanatory devices in the classroom. However, research has sho wn that analogies can engender alternative conceptions because some st udents visualize the analog in a different manner than the teacher and /or invalid analog-target transfers are left unchallenged. This case s tudy describes one teacher's implementation of a modified version of G lynn's Teaching-With-Analogies (TWA) model with a Grade-10 optics clas s on refraction of light. The analogy likened a ray of light as it pas ses 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 indic ates that a competent teacher can integrate this systematic approach i nto a teaching repertoire resulting in student conceptual understandin g of the phenomena as expected at this level of science education. For analogies to be effective, it appears essential that the analogy be f amiliar to as many students as possible, that shared attributes be pre cisely identified by the teacher and/or students, and that the unshare d attributes should be explicitly identified. The discussion concludes with recommendations for teaching and future research and discusses s ome limitations of this approach to analogical instruction.