Table 4.

Mean scores compared with paired-samples t-test (and related effect sizes) for non-problem gamblers (n = 44) and at-risk/problem gamblers (n = 12) in the experimental group

	Pre-test		Post-test		T	d
	M	SD	M	SD
Total hours
Non-problem gamblers	0.06	0.14	0.05	0.13	0.34 (n.s.)	–
At-risk/problem gamblers	0.54	0.28	0.19	0.23	3.74*	1.08
Knowledge about gambling
Non-problem gamblers	22.34	3.01	26.23	3.03	− 6.64***	1
Misconceptions
At-risk/problem gamblers	21.42	3.12	26.17	5.10	− 2.97*	0.86
Non-problem gamblers	17	2.44	12.32	2.67	8.74***	1.32
At-risk/problem gamblers	17.75	1.71	12.92	3.55	3.87**	1.12
Attitudes
Non-problem gamblers	23.77	3.78	20.80	4.28	3.69**	0.56
At-risk/problem gamblers	24.92	3.06	22.75	2.86	1.79 (n.s.)	–

n.s. non-significant

*p < 0.05; **p < 0.01; ***p < 0.001