Table 2.

Summary of linear regression analyses predicting word accuracy for children in Grades 3 and 5.

Step	Predictor	B	ΔR2	Predictor	B	ΔR2	Predictor	B	ΔR2
1	Surface frequency	-0.152	0.241∗
	Semantic relatedness	0.204
	N size of base	0.537
	N size of derived form	-0.050
2	Family size	0.206	0.039	Base frequency	0.376	0.137∗	Family frequency	0.275	0.066ˆ
3	Family frequency	0.241	0.028	Family size	0.099	0.008	Base frequency	0.337	0.073∗
4	Base frequency	0.349	0.077∗	Family frequency	-0.004	0.000	Family size	0.101	0.005

ˆp < 0.1, ^∗p < 0.05; reported Beta weights are Step Betas. N, neighborhood. Values at Step 2 show the effects of each of family size, base frequency and family frequency after controlling for surface frequency, semantic relatedness and the neighborhood size of the base word and its derived form. Values at Step 4 show the effects of each of family size, base frequency and family frequency after controlling for surface frequency and semantic relatedness, in addition to the other two variables.