Effective teaching of energy in mechanics

Abstract

Science learners come to class with pre-instructional ideas that may influence the acquisition of science concepts. A basic assumption of the constructivist learning theory is that these pre-instructional ideas should be taken into account in constructing learners' conceptual frameworks in science classes. Several conceptual change strategies have been studied in order to alter unscientific (called alternative) conceptions towards the scientifically accepted conceptions. The challenging task of the science educator is to select appropriate teaching strategies and techniques that will enhance learning. The study reported here investigates the effectiveness of an activity-based approach in the teaching of energy in Grade 10 Physical Sciences. The approach takes into account the prior beliefs adhered to by learners. A learning sequence was developed, presenting a variety of problems in such a way and order that learners' conceptions could progressively be changed from their alternative conceptions to the scientific conceptions. The sequence progressed from contextual to conceptual to formal activities. Co-operative learning, inquiry, verbalisation and analogous reasoning techniques were used to guide learners in the acquisition of the scientific concepts. The approach is based on the assertion that learners' scientific knowledge and understanding are socially constructed through talk, activity and interaction around meaningful problems and tools. Consequently, this activity-based strategy is in line with contemporary learner-centred approaches as manifested in the National Curriculum Statement for FET physical sciences. The research population consisted of fifty five (55) physical science learners enrolled at the Hans Kekana High School in a rural village, Majaneng, in the Gauteng Province. The questionnaire that served as pre- and post-test probed into learners' alternative conceptions of energy. The effectiveness of the intervention was indicated by the amount of conceptual change accomplished that followed from a calculation of the normalised learning gain.