Table 3.

Hierarchical multiple regression analysis summary for the factors predicting infants’ vocabulary size at 19 months.

Variable	R2	R2 change	Coefficient B	SE B	β	p-value	95% CI for B
							Lower	Upper
Step 1	0.20	0.20
Number of types			1.59	0.51	0.45	<0.01	0.56	2.62
Constant			−59.82	56.72
Step 2	0.32	0.12
Number of types			1.35	0.48	0.39	<0.01	0.37	2.33
Proportion looking to target			3.41	1.33	0.35	<0.05	0.71	6.11
Constant			−277.01	100.06