Abstract:

Science students 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 students' learning experiences in science classes. A number of conceptual change strategies have been studied in order to alter unscientific (also 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.

This study investigated students’ alternative conceptions about electric circuits and the effect of activity-based instructional approaches in ameliorating these alternative conceptions. The approach took into account the prior beliefs of the students. A learning sequence was developed, presenting a variety of learning experiences in such a way and order that learners' alternative conceptions could progressively be changed into scientifically accepted ones. The sequence progressed from contextual to conceptual to formal activities. Co-operative learning, scientific enquiry, verbalisation and analogous reasoning techniques were used to guide learners in the acquisition of scientific concepts. The approach was based on the assertion that learners' scientific knowledge and understanding are socially constructed through talk, activity and interaction around meaningful problems and tools.
The research population consisted of hundred (100) first-year science students enrolled at a South African university both from the NCS and the OSC (Nated 550). The test that served as pre- and post-test probed into learners' alternative conceptions about electric circuits. A theoretical framework, based on activity-theory as it is applied in a constructivist view of learning, was developed. A pre-post-test comparison group design was followed. In particular, the pre-test helped to identify alternative conceptions held by the students in the research sample. This was then followed by activity-based interventions within the pedagogical aegis of OBE with a view to alleviate the identified alternatives conceptions. These interventions were followed by a post-test in order to ascertain the effectiveness of the interventions in alleviating the identified alternative conceptions. Both quantitative and qualitative data were collected. From the quantitative data, using McNemar and “t” test, the findings showed highly statistically significant gains between the pre- and post-test scores of both the OBE and OSC groups (p < 0, 05), thus indicating the effectiveness of the intervention. The qualitative data showed that most of the alternative conceptions appeared to have been alleviated, No statistically significant difference was found between the normalised gains of OBE and OSC groups.

Keywords:

Alternative conceptions, conceptual change, electric circuits, activity-based instructional approaches, teaching strategies, activity-theory.