Table 1.

Demographic characteristics of the participants.

	GG-FL				AC				PC				Statistic(df)	p
	n	M	SD	Med	n	M	SD	Med	n	M	SD	Med
Age in months at pre-test	31	65.5	3.4	65.0	29	65.8	3.4	65.0	28	66.9	3.3	67.0	H(2) = 3.37	0.186b
Non-verbal IQa	31	101.2	16.9	101.9	29	96.3	13.4	95.5	28	94.9	14.3	93.4	F(2, 85) = 1.43	0.246c
HLE (frequency of joint literate activities)a	29	−0.19	0.90	−0.17	25	−0.25	1.12	−0.27	28	0.30	0.83	0.29	F(2, 79) = 2.75	0.070c
HLE (number of books at home)e	29	0.26	1.07	0.68	25	0.12	1.16	0.64	28	0.05	0.83	0.19	H(2) = 2.73	0.255b
HLE (duration and frequency of reading)e	29	−0.18	0.82	−0.49	25	0.13	1.04	−0.50	28	0.09	0.97	−0.39	H(2) = 3.75	0.153b
HLE (duration of joint literate activities)e	29	−0.16	0.96	−0.76	25	0.13	1.06	−0.67	28	0.25	1.03	0.26	H(2) = 4.25	0.119b
Maternal ARHQ scoree	30	0.06	0.86	−0.13	25	0.03	0.70	−0.10	28	−0.14	0.61	−0.10	H(2) = 0.37	0.833b
Paternal ARHQ scoree	21	0.33	1.29	0.27	22	0.57	0.95	0.76	28	−0.24	0.49	−0.08	H(2) = 12.32	0.002b*
Gender (female/male)	31	16/15			29	13/16			28	17/11			χ2(2) = 1.45	0.484d
SES (low/middle/high/unknown)	31	7/12/12/0			29	8/15/5/1			28	7/14/7/0			${\chi }_{(4)}^2$ = 3.39	0.495d

GG-FL, GraphoGame Flemish group; AC, active control group, PC, passive control group; df, degrees of freedom; IQ, intelligence quotient; HLE, home literacy environment; ARHQ, adult reading history questionnaire; SES, socio-economic status; n, number of participants; M, mean; SD, standard deviation; Med, median. For categorical variables (gender and SES), the number of children in each subcategory is reported.

^aStandardized scores (M = 100, SD = 15).

^bIndependent-Samples Kruskal Wallis Test.

^cOne-way Anova test.

^dPearson Chi-Square test.

^eStandardized factor scores based on parental screening questionnaires.

^*p < 0.050.