“…In the experimental group, which included fifth-grade students, 92.9% (39 of the 42 students) agreed to participate as compared to 60.2% (50 of the 83 students) in the control group. Additionally, we chose fifth-grade students based on the results of a previous study that reported that the optimal and effective period for CSA prevention education is the fourth to sixth grade of elementary school (Ha & Lee, 2014;Im & Park, 2014;Kim et al, 2013). During this period, the awareness of sexuality develops more concretely, secondary sexual characteristics begin to appear, and intimacy with those of the opposite sex increases; therefore, they develop more interest in and think more specifically about sexuality than they do before (Choi, 2010).…”