Table 1.

Mean (standard deviation) and effect size (Cohen’s d) of mental rotation measures in the pretest and post-test and the pre-post-test differences (increases) for control group and training group in 1st course of Preschool Education.

	Pretest	Post-test	Increase	d
Control group (N = 29)	4.75	5.32	0.57∗
	(1.17)	(1.25)	(1.1)
				*0.50
Training Group (N = 29)	4.96	6.11	1.15∗
	(1.02)	(1.4)	(1.23)

^∗p < 0.05, ^∗∗p < 0.01.