Identifying common misconceptions as an effective strategy for teaching light in physics

It is observed that a significant number of misconceptions about the nature and behaviour of light is experienced by students at the upper secondary level. A modified teaching methodology, based on the 'conflict' approach, was explored to bring about deeper conceptual understanding about the properties of light. In this approach, teachers make a conscious effort to surface common learning difficulties or misconceptions faced by students in a particular topic. These are then presented to and discussed with students in an additional lesson at the end of the topic.

The 'conflict' approach can be contrasted to the 'positive only' approach which advocates designing lessons which are closely aligned to the syllabus content. Such lessons leave minimal room for discussions of common learning difficulties by students. A study by Askew and William (1995) stated that while both approaches were effective in Mathematics education, the 'conflict' approach was significantly more effective over the longer term. Our team believed that similar results may be found in Physics education, due to the closely inter-woven nature of both subjects. Tzanakis (2002) states 'any treatment of the history of Mathematics, independent of the history of Physics, is necessarily incomplete (and vice versa)'. Physical concepts, arguments and modes of thinking are used in Mathematics and mathematical methods are used in expressing, handling and logically developing physical concepts and theories.

In this study, a team of Physics teachers conducted lessons on Light, solely based on the syllabus content, with a group of Secondary Three Express students of varying abilities. A two-tier diagnostic pre-test was administered to the students to assess their conceptual understanding. The teacher of the experimental group then conducted an additional lesson, identifying and discussing some of the common misconceptions faced by students when learning the topic on Light. The teacher of the control group spent the additional lesson reinforcing the concepts taught using the 'positive only' approach. A post-test, of similar difficulty level to the pre-test, was then administered to assess if there was any change in the students' level of understanding. The data collected showed statistically significant differences in test scores of students in the experimental group.

In this project, the 'conflict' approach was applied for only a single topic and significant improvement was observed for some test items. The project can be further developed to include various topics over a longer period to ascertain its effectiveness in the teaching and learning of Physics concepts.