Fig. 2: Histograms showing the distribution of the change in scores for students taking both pre and post tests for both tranches.
a Tranche 1: pre-test mean = 5.51 ± 2.15, post-test mean = 7.92 ± 2.38; b tranche 2: pre-test mean = 5.77 ± 2.25, post-test mean = 8.09 ± 2.70.
