Table 3. Summary of Hierarchical Linear Regression Analyses Using IQ, Speed Indices, and Executive Function, as Predictors for Mathematics and Attention Problems.

Step	Predictor	ΔR2	P	β	P
	Preschool
	Mathematics
1	Groupa	.34	<.001	−.35	.006
2	Groupa	.46	.007	−.17	.21
	IQ			.35	.007
Parent	Rated Attention Problems
1	Groupa	.13	.006	.32	.004
4	Groupa	.18	.04	.26	.03
	Impulse Control			.25	.04
Teacher	Rated Attention Problems
1	Groupa	.20	.003	.41	.003
	Primary School
	Mathematics
1	Groupa	.80	<.001	−.11	.01
4	Groupa	.84	<.001	−.04	.16
	Speed Indices			−.05	.10
	IQ			.16	<.001
	Visuospatial Span			.13	<.001
Parent	Rated Attention Problems
1	Groupa	.21	<.001	.23	<.001
4	Groupa			.15	.04
	IQ			−.14	.06
	Visuospatial Span			−.16	.04
Teacher	Rated Attention Problems
1	Groupb	.25	.01	.30	<.001
	Group*Gender			−.23	.005
4	Groupb	.38	.009	.18	.01
	Group*Gender			−.18	.03
	IQ			−.005	.96
	Group*IQ			−.24	.02
	Visuospatial Span			−.19	.009
	Impulse Control			.19	.005

Significant associations (P<.05) are shown in bold type.^aEffects of group have been adjusted for grade or age, gender, and most prestigious level of parental education.^bEffects of group have been adjusted for grade or age, and most prestigious level of parental education.