Table 7.

Conditional growth model parameters including interactions between SLI and covariates.

Parameter	Missing Do Total R2 = .175					Ungrammatical Lex Total R2 = .184					Ungrammatical Do + Lex Total R2 = .215					Double Tense Total R2 = .242
	Est	SE	95% CI		p <	Est	SE	95% CI		p <	Est	SE	95% CI		p <	Est	SE	95% CI		p <
			LL	UL				LL	UL				LL	UL				LL	UL
Fixed effects
Int (age 10 years)	.80	.02	.77	.84	.001	.82	.02	.78	.86	.001	.87	.02	.84	.91	.001	.74	.02	.70	.78	.001
Linear age slope	.19	.03	.13	.26	.001	.12	.04	.05	.19	.001	.19	.04	.12	.26	.001	.28	.03	.21	.35	.001
Quad age slope	−.29	.03	−.35	−.23	.001	−.40	.09	−.58	−.22	.001	−.38	.03	−.44	−.32	.001	−.18	.03	−.24	−.12	.001
Linear age cohort	.10	.02	.06	.14	.001	.08	.02	.04	.12	.001	.09	.02	.05	.14	.001	−.01	.02	−.05	.03	.557
Quad age cohort																.18	.07	.06	.31	.005
SLI on int	−.09	.02	−.13	−.04	.001	−.12	.03	−.17	−.06	.001	−.08	.02	.12	−.04	.001	−.11	.02	−.15	−.07	.001
SLI on slope	−.03	.04	−.12	.05	.442	.02	.05	−.08	.11	.704	.05	.05	−.04	.15	.276	−.06	.05	−.15	.03	.188
SLI on quad						.12	.13	−.13	.36	.365
NVIQ on int	.00	.00	.00	.00	.216	.00	.00	.00	.00	.088	.00	.00	.00	.00	.147	.00	.00	.00	.00	.405
NVIQ on slope	.00	.00	.00	.00	.264	.00	.00	.00	.00	.915	.00	.00	.00	.00	.860	.00	.00	.00	.00	.780
NVIQ on quad						−.01	.00	−.02	.00	.026
NVIQ × SLI on int	.00	.00	.00	.00	.231	.00	.00	.00	.00	.161	.00	.00	.00	.00	.047	.00	.00	.00	.00	.276
NVIQ × SLI on slope	.00	.00	.00	.00	.791	.00	.00	.00	.01	.444	.00	.00	.00	.00	.928	.00	.00	.00	.01	.167
NVIQ × SLI on quad						.00	.01	−.01	.01	.824
M-Ed on int	.02	.01	.01	.03	.006	.01	.01	−.01	.03	.242	.01	.01	.00	.03	.066	.02	.01	.01	.03	.003
M-Ed on slope	.00	.01	−.02	.03	.767	.02	.01	−.01	.05	.131	.01	.01	−.02	.03	.662	.03	.01	.00	.06	.023
M-Ed on quad						.05	.03	−.02	.11	.185
M-Ed × SLI on int	.00	.01	−.02	.02	.986	.01	.01	−.02	.03	.580	.01	.01	−.01	.03	.302	.00	.01	−.02	.01	.756
M-Ed × SLI on slope	.01	.02	−.02	.05	.475	−.02	.02	−.05	.02	.379	−.01	.02	−.05	.03	.537	−.01	.02	−.05	.02	.423
M-Ed × SLI on quad						−.06	.05	−.16	.03	.202
BvG on int	−.02	.02	−.05	.01	.262	.00	.02	−.04	.05	.901	−.01	.02	−.04	.02	.539	−.02	.02	−.05	.01	.225
BvG on slope	−.09	.03	−.15	−.02	.010	−.06	.04	−.13	.01	.118	−.08	.04	−.15	−.01	.021	−.06	.03	−.13	.00	.069
BvG on quad						.07	.09	−.12	.25	.473
BvG × SLI on int	.00	.02	−.05	.05	.988	.02	.03	−.04	.07	.610	−.02	.02	−.06	.03	.465	.01	.02	−.04	.05	.762
BvG × SLI on slope	.07	.05	−.02	.16	.134	.06	.05	−.04	.16	.223	.05	.05	−.05	.15	.316	.07	.05	−.03	.16	.177
BvG × SLI on quad						−.18	.13	−.44	.08	.170
Random effects: Variance components
L1 residual	.04	.00	.03	.04	.001	.03	.00	.03	.04	.001	.03	.00	.03	.03	.001	.04	.00	.03	.04	.001
L2 int	.01	.00	.01	.02	.001	.00	.00	.00	.01	.008	.01	.00	.01	.01	.001	.01	.00	.01	.01	.001
L2 linear	.01	.00	.00	.03	.010	.02	.00	.01	.03	.001	.02	.00	.02	.04	.001	.01	.00	.01	.03	.001
L2 quad	.03	.02	.01	.31	.088	.10	.03	.06	.19	.001	.05	.03	.02	.19	.023
L2 int–linear	.01	.00	.00	.01	.001	.00	.00	.00	.00	.916	.00	.00	.00	.00	.617	.00	.00	.00	.01	.001
L2 int–quad	−.02	.01	−.03	−.01	.001	−.03	.01	−.04	−.02	.001	−.02	.00	−.03	−.01	.001
L2 lin–quad	−.01	.01	−.02	.00	.032	.00	.01	−.02	.01	.876	.01	.01	.00	.03	.089
L3 int	.00	.00	.00	.01	.032	.01	.00	.01	.02	.001	.00	.00	.00	.01	.001	.00	.00	.00	.01	.003

Note. The time-varying predictor of age and the effects of age cohort were log-transformed. The estimates for linear and quadratic effects of age cohort represent the cross-sectional effects of children's exact age at study entry, centered at log-age 8 years, on the intercept. The intercept for each GJ Complex outcome reflects the expected A′ score for a 10-year-old girl, without SLI who entered the study at 8 years of age with average-level performance on nonverbal IQ and whose mother has a high school education or GED. The Est for SLI reflects the difference in A′ score for SLI affected compared to unaffected children; the Est for NVIQ reflects the increase in A′ score for each one-unit increase in IQ score; the Est for M-Ed reflects the increase in A′ score for each one-unit increase in maternal education; the Est for BvG reflects the difference in A′ score for boys when compared to girls. Bold values indicate p < .01. Covariances indicated with dash (–). Blank cells indicate effects not included in a particular model due to nonsignificance. SLI = specific language impairment (0 = unaffected); Est = estimate; SE = standard error; CI = confidence interval; LL = lower limit; UL = upper limit; Int = intercept; Quad = quadratic; NVIQ = nonverbal IQ (centered at 100); M-Ed = maternal education (0 = high school/GED); BvG = boys versus girls (0 = girls); L1 residual = variance over time and within persons; L2 = Level 2: variance across persons within families; L3 = Level 3: variance within families; GJ = grammaticality judgment; GED = general equivalency diploma.