Table 2.

Pretest and posttest radiation safety knowledge scores among matched participants (n = 69)

Variable	Pretest	Posttest
Total knowledge score, mean ± SD	3.06 ± 3.00	6.78 ± 3.83
Median	3.0	7.0
Minimum–maximum	0–12	0–14
Cronbach’s alpha	0.81	0.82
p value		6.36 × 10 − 9
Effect size		r = 0.70

Knowledge scores were calculated using 15 repeated items. The Wilcoxon signed-rank test was used because pretest-posttest difference scores were not normally distributed