This work is licensed under a Table 5.
Final conditional growth model parameters.
| Parameter | Missing Do Total R2 = .174 |
Ungrammatical Lex Total R2 = .181 |
Ungrammatical Do + Lex Total R2 = .214 |
Double Tense Total R2 = .241 |
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 | .01 | .77 | .83 | .001 | .81 | .02 | .77 | .84 | .001 | .86 | .01 | .83 | .89 | .001 | .74 | .02 | .71 | .77 | .001 |
| Linear age slope | .17 | .03 | .11 | .22 | .001 | .12 | .03 | .06 | .18 | .001 | .19 | .03 | .13 | .25 | .001 | .27 | .03 | .22 | .33 | .001 |
| Quad age slope | −.29 | .03 | −.35 | −.23 | .001 | −.30 | .07 | −.45 | −.16 | .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 | .13 | .001 | −.02 | .02 | −.06 | .03 | .463 |
| Quad age cohort | .19 | .07 | .06 | .31 | .004 | |||||||||||||||
| SLI on int | −.08 | .01 | −.11 | −.06 | .001 | −.10 | .02 | −.13 | −.07 | .001 | −.08 | .01 | −.10 | −.05 | .001 | −.11 | .01 | −.14 | −.09 | .001 |
| SLI on slope | .02 | .02 | −.03 | .07 | .398 | .03 | .03 | −.02 | .08 | .301 | .06 | .03 | .01 | .11 | .022 | −.04 | .03 | −.09 | .01 | .097 |
| SLI on quad | −.08 | .07 | −.22 | .05 | .236 | |||||||||||||||
| NVIQ on int | .00 | .00 | .00 | .00 | .004 | .00 | .00 | .00 | .00 | .001 | .00 | .00 | .00 | .00 | .001 | .00 | .00 | .00 | .00 | .031 |
| NVIQ on slope | .00 | .00 | .00 | .00 | .210 | .00 | .00 | .00 | .00 | .400 | .00 | .00 | .00 | .00 | .977 | .00 | .00 | .00 | .00 | .096 |
| NVIQ on quad | −.01 | .00 | −.01 | .00 | .003 | |||||||||||||||
| M-Ed on int | .02 | .00 | .01 | .03 | .001 | .01 | .01 | .00 | .02 | .029 | .02 | .01 | .01 | .03 | .001 | .02 | .00 | .01 | .03 | .001 |
| M-Ed on slope | .01 | .01 | −.01 | .03 | .290 | .01 | .01 | −.01 | .03 | .260 | .00 | .01 | −.02 | .02 | .966 | .02 | .01 | .00 | .04 | .019 |
| M-Ed on quad | .01 | .02 | −.03 | .06 | .578 | |||||||||||||||
| BvG on int | −.02 | .01 | −.04 | .00 | .117 | .01 | .02 | −.02 | .04 | .458 | −.02 | .01 | −.04 | .00 | .117 | −.02 | .01 | −.04 | .01 | .166 |
| BvG on slope | −.05 | .02 | −.10 | −.01 | .025 | −.03 | .03 | −.08 | .02 | .301 | −.06 | .03 | −.11 | −.01 | .020 | −.03 | .02 | −.08 | .02 | .239 |
| BvG on quad | −.01 | .07 | −.14 | .11 | .837 | |||||||||||||||
| 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 | .01 | .00 | .01 | .02 | .001 | .01 | .00 | .01 | .01 | .001 | .01 | .00 | .01 | .01 | .001 |
| L2 linear | .01 | .00 | .01 | .03 | .008 | .02 | .00 | .01 | .03 | .001 | .02 | .00 | .02 | .04 | .001 | .01 | .00 | .01 | .03 | .001 |
| L2 quad | .03 | .02 | .01 | .33 | .094 | .09 | .03 | .05 | .19 | .001 | .05 | .03 | .02 | .19 | .022 | |||||
| L2 int–linear | .01 | .00 | .00 | .01 | .001 | .00 | .00 | .00 | .00 | .929 | .00 | .00 | .00 | .00 | .622 | .00 | .00 | .00 | .01 | .001 |
| L2 int–quad | −.02 | .01 | −.03 | −.01 | .001 | −.03 | .01 | −.04 | −.02 | .001 | −.02 | .00 | −.03 | −.01 | .001 | |||||
| L2 linear–quad | −.01 | .01 | −.03 | .00 | .023 | .00 | .01 | −.01 | .01 | .961 | .01 | .01 | .00 | .03 | .100 | |||||
| L3 int | .00 | .00 | .00 | .01 | .039 | .00 | .00 | .00 | .01 | .012 | .00 | .00 | .00 | .01 | .001 | .00 | .00 | .00 | .01 | .004 |
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. Est = estimate; SE = standard error; CI = confidence interval; LL = lower limit; UL = upper limit; Int = intercept; Quad = quadratic; SLI = specific language impairment (0 = unaffected); 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.