“…Table 3 shows three out of the four studies examining knowledge/learning had 95% confidence intervals that did not contain zero, thereby indicating the effect size is significantly different from zero, which indicates differences in treatment effect between the experimental and control group. Of these three studies, one study (Arnold, Smith, Harrison, & Springer, 1999) had a medium effect size (d = .45) while two studies (Barth, Fetro, Leland, & Volkan, 1992;Dhooper & Schneider, 1995) had large effect sizes, d = .87 and d = .82, respectively. The other study (Corcoran, 2006) had an effect size of .06, and the effect size was not significantly different from zero.…”