Abstract:

The present study aims to investigate the effectiveness of video-based instruction in a course entitled "Environmental Studies" to impart environmental knowledge among undergraduate students. The pretest-posttest assessment method was employed to obtain the scores before and after showing a video on a selected environmental theme to three different class sizes consisting of 9 (small class size), 19 (average class size), and 34 (large class size) students enrolled in three different semesters. The students enrolled in these classes were of varying demographics i.e., nationality, age and gender. The gains in student knowledge were determined using a two-tailed paired t-tests and effect size was analyzed using Cohen’s d. The difference in pretest-posttest score in the small class was highest (24.2%) using two-tailed paired t-test: t(8), p < 0.005 with a very large effect size (Cohen's d = 2.52). The differences between the pretest-posttest scores for the average class size was 23.9% (t(18), p < 0.001, Cohen's d = 1.65) and for the large class size was 17.9% (t(33), p < 0.001, Cohen's d = 1.06). The data demonstrates that all three classes gained knowledge by video-based instruction method in the environmental course and the knowledge gain has a negative correlation with the size of the class.