The Effectiveness of Lecture Demonstrations to Enhance Learning of Chemistry

Abstract

Two methods for teaching a 12th grade chemistry course were compared by carrying out a two-group differential investigation in order to evaluate the effectiveness of using lecture demonstrations to improve student learning. The sample was students of four classes at a public girls’ high school in Tehran. Initial equivalence between four classes was checked by a standard I.Q.-estimating test and a chemistry knowledge evaluating pretest, the results of which showed no significant difference between averages of four classes. In two classes of experimental group, alongside teaching the chemistry textbook, 11 demonstrations planned in relation with topics to be taught were conducted on appropriate occasions. In the other two classes, the control group, only the textbook was taught. After having taught each topic to both groups they were to answer an identical written quiz on that topic. In all, there were nine quizzes of the kind during the semester and an identical end-of-semester examination of all topics taught in this chemistry course. A statistical analysis of the results of all assessments, using t-test, showed with a very high confidence level that students in the experimental group achieved higher scores than students in the control group. Considering the initial equivalence between four classes, identical instructor, and similarity in teaching method and all aspects and conditions of this study, the results suggest that using lecture demonstrations is a much more effective means of instruction than traditional lecturing method.