Table 4.
Bayesian regression output broken down by model (Year 2 outcome and Year 1 predictors), informative prior distributions (priors and sources are listed) versus weakly informative prior distributions, and within-group follow-up regression.
| Regression model | B | SD | HPD interval | Penalized deviance | Bayes p value | Prior |
Source | |
|---|---|---|---|---|---|---|---|---|
| TD | SLI | |||||||
| Year 2 inhibition RT | ||||||||
| Year 1 morphology | ||||||||
| Informative | 8,765 | .504 | 300ms | 400ms | Kail, 1994; McElree, 2001; Schul et al., 2004; Van Dyke & Johns, 2012 | |||
| Intercept | 459.480 | 30.753 | 399.149, 528.983 | |||||
| Group | 126.112 | 28.844 | 69.834, 181.687 | |||||
| Morphology | 6.886 | 3.286 | 0.571, 13.398 | |||||
| Group × Morphology | −8.280 | 3.667 | −15.454,−1.226 | |||||
| Age | 5.462 | 3.409 | −1.250, 11.953 | |||||
| Weakly informative | 8,765 | .501 | 0.001 | 0.001 | ||||
| Intercept | 129.127 | 31.131 | 66.528, 187.482 | |||||
| Group | 32.944 | 28.431 | −23.607, 86.422 | |||||
| Morphology | 14.986 | 3.578 | 7.863, 21.779 | |||||
| Group × Morphology | 3.578 | 3.712 | −3.265, 11.146 | |||||
| Age | 29.920 | 3.742 | 22.606, 37.093 | |||||
| Within-group SLI Informative | 3,870 | .500 | 400ms | Kail, 1994; McElree, 2001; Schul et al., 2004; Van Dyke & Johns, 2012 | ||||
| Intercept | 456.254 | 30.754 | 399.888, 521.376 | |||||
| Morphology | 2.499 | 6.144 | −9.081, 14.904 | |||||
| Age | 11.672 | 4.763 | 2.270, 20.891 | |||||
| Within-group TD Informative | 4,872 | .504 | 300ms | Kail, 1994; McElree, 2001; Schul et al., 2004; Van Dyke & Johns, 2012 | ||||
| Intercept | 353.063 | 30.454 | 295.712, 414.010 | |||||
| Morphology | 13.608 | 3.464 | 7.141, 20.789 | |||||
| Age | 6.773 | 4.277 | −2.097, 14.801 | |||||
| Year 1 vocabulary | ||||||||
| Informative | 8,374 | .499 | 300ms | 400ms | Kail, 1994; McElree, 2001; Schul et al., 2004; Van Dyke & Johns, 2012 | |||
| Intercept | 422.653 | 30.595 | 362.083, 481.899 | |||||
| Group | 119.542 | 30.775 | 59.664, 179.670 | |||||
| Vocabulary | 1.699 | 0.434 | 0.840, 2.542 | |||||
| Group × Vocabulary | −0.677 | 0.352 | −1.367, 0.022 | |||||
| Conners t score | 1.701 | 0.437 | 0.832, 2.546 | |||||
| Age | −12.558 | 4.547 | −21.751, −3.989 | |||||
| Weakly informative | 8,785 | .499 | 0.001 | 0.001 | ||||
| Intercept | 89.805 | 30.708 | 29.898, 149.884 | |||||
| Group | 17.712 | 30.764 | −40.803, 79.515 | |||||
| Vocabulary | 2.928 | 0.459 | 2.003, 3.800 | |||||
| Group × Vocabulary | 0.408 | 0.358 | −0.285, 1.112 | |||||
| Conners t score | 2.082 | 0.455 | 1.190, 2.973 | |||||
| Age | 3.983 | 4.749 | −5.285, 13.241 | |||||
| Within-group SLI informative | 3,857 | .500 | 400ms | Kail, 1994; McElree, 2001; Schul et al., 2004; Van Dyke & Johns, 2012 | ||||
| Intercept | 441.850 | 31.436 | 379.878, 502.911 | |||||
| PPVT | 0.162 | 0.992 | −1.807, 2.085 | |||||
| Conners t score | 3.598 | 0.894 | 1.845, 5.353 | |||||
| Age | −11.294 | 7.183 | −25.296, 2.898 | |||||
| Within-group TD informative | 4,864 | .500 | 300 ms | Kail, 1994; McElree, 2001; Schul et al., 2004; Van Dyke & Johns, 2012 | ||||
| Intercept | 333.504 | 30.680 | 272.920, 393.641 | |||||
| PPVT | 2.198 | 0.423 | 1.365, 3.027 | |||||
| Conners t score | 0.862 | 0.479 | −0.069, 1.817 | |||||
| Age | −6.822 | 5.502 | −18.077, 3.662 | |||||
| Year 2 morphology | ||||||||
| Year 1 inhibition RT | ||||||||
| Informative | 3,101 | .501 | 11 | 7 | Kaushanskaya et al., 2017; Norbury et al., 2016; Tomblin et al., 1997 | |||
| Intercept | 10.321 | 0.330 | 9.668, 10.968 | |||||
| Group | −2.034 | 0.658 | −3.326, −0.760 | |||||
| Inhibition RT | −0.002 | 0.001 | −0.003, −0.000 | |||||
| Group × Inhibition RT | −0.003 | 0.008 | −0.005, −0.001 | |||||
| Within-group SLI informative | 1,166 | .500 | 7 | Kaushanskaya et al., 2017; Norbury et al., 2016; Tomblin et al., 1997 | ||||
| Intercept | 9.157 | 1.387 | 6.427, 11.917 | |||||
| Inhibition RT | −0.003 | 0.001 | −0.004, −0.002 | |||||
| Age | 0.011 | 0.111 | −0.207, 0.232 | |||||
| Within-group TD informative | 1,875 | .500 | 11 | Kaushanskaya et al., 2017; Norbury et al., 2016; Tomblin et al., 1997 | ||||
| Intercept | 14.009 | 1.823 | 10.432, 17.649 | |||||
| Inhibition RT | −0.001 | 0.001 | −0.002, 0.001 | |||||
| Age | −0.233 | 0.153 | −0.538, 0.067 | |||||
Note. All models included predictors that met our ≥ 90% posterior inclusion probability criterion in Bayesian model averaging analyses, and all priors had low precision (0.001) due to the novelty of analyses. HPD = highest posterior density; TD = typically developing; SLI = specific language impairment; RT = inhibition reaction time; Morphology = morphological comprehension measured by Test of Language Development: Intermediate–Fourth Edition Morphological Comprehension subscale (Hammill & Newcomer, 2008); Vocabulary = receptive vocabulary measured by the Peabody Picture Vocabulary Test–Fourth Edition (Dunn & Dunn, 2007); Conners t scores = ADHD Rating Scale (Conners et al., 2008).