Table 1.
Estimates of fixed effects, random effects, and goodness of fit for cubic growth models using parent SES, and parent word types to predict intercept and change in children’s cumulative vocabulary.
| Parameter Estimate (SD)
|
|||
|---|---|---|---|
| Model 1 (Cubic) | Model 2 (Adding SES) | Model 3 (Adding Input) | |
| Fixed Effects | |||
| Intercept | 470.29*** (33.44) |
470.28*** (32.25) |
470.28*** (32.91) |
| Linear change | 26.52*** (1.36) | 26.52*** (1.19) | 26.56*** (1.21) |
| Quadratic change | 0.07 (0.04) | 0.06 (0.04) | 0.07 (0.05) |
| Cubic change | −0.01*** (0.01) | −0.01*** (0.01) | −0.01*** (0.01) |
| SES | 50.27 (33.18) | 65.64 (42.40) | |
| SES × Age | 3.06** (1.17) | 3.62** (1.50) | |
| SES × Age2 | 0.06 (0.05) | 0.03 (0.06) | |
| Input | −0.16 (0.27) | ||
| Input × Age | −0.01 (0.01) | ||
| Input × Age2 | 0.01 (0.01) | ||
| Random effects | |||
| Level 2 | |||
| Intercept | 20,059*** (141.63) |
18,635.98*** (136.51) |
19,410.39*** (139.32) |
| Linear change | 30.87*** (5.56) | 22.89*** (4.78) | 23.83 (4.88) |
| Quadratic change | 0.04*** (0.19) | 0.03*** (0.19) | 0.04*** (0.19) |
| Goodness of fit | |||
| Deviance (−2LL) | 2217.41 (7) | 2197.53 (7) | 2227.87 (7) |
*
p<.05,
**
p<.01,
***
p<.001