Abstract:
Traditional methods of teaching adopted by Nigerian Physics teachers which do not address alternative conceptions students have before coming to physics classes partly account for poor physics achievement demonstrated by Nigerian physics students (Ivowi, 1984; Otuka, 1987; Gcorgewill, 1996; Eze, 2000). These alternative conceptions which the students seem to have, had been found to be inconsistent with the content to be learned and also hinder effective learning of' physics contents (Webb, , 7 1992). This resultant poor physics achievement may contribute to loss of interest, low physics enrolment and dearth of physics teachers. As a result, national development might be greatly impeded since physics is one of the basic sciences needed for technological development. There is the need therefore to explore constructivist-based models like analogy and conceptual-change instructional models which take students' conception positions as starting points for instructions (Brown, 1994 and Nworgu, 1996b). 'I'his study, therefore, was designed to investigate the effects of analogy and conceptual-change instructional models on physics achievement of boys and girls taught simple electric circuit in Enugu state senior secondary schools. Four research questions and three hypotheses were formulated to guidc the study. To carry out the study, a non equivalent, pretest-posttest quasi-experimental design was employed. Physics Achievement test developed by the researcher was used to collect relevant data from a sample of 185 students selected from Enugu state senior secondary class one students within Enugu education zone. Five experts carried out face and content validations of the instrument. Also reliability coefficient of 0.86 was computed for the instrument using Kuder Richardson formular 20. Percentage, mean and standard deviation scores were used to answer the research questions while analysis of covariancc was used to test the three hypotheses at an alpha level of 0.05. The study among other things revealed that 92 percent of students used for this study who have alternative conceptions before formal physics instructions took place shifted from their initial conception positions to the standard scientific views after the treatment. 'Ihe study also revealed that analogy and conceptual-change instructional models have allnost identical pattern in facilitating and enhancincing conceptual change and achievement in Physics. It was recommended that analogy and conceptual-change instructional models be adopted in Nigerian physics instructions.
