Table 4.

Estimates of the unconditional linear growth curve models for spelling accuracy, handwriting speed, and handwriting quality.

	Cohort 1			Cohort 2
	Spelling	Speed	Quality	Spelling	Speed	Quality
	Estimate [95% BCI]	Estimate [95% BCI]	Estimate [95% BCI]	Estimate [95% BCI]	Estimate [95% BCI]	Estimate [95% BCI]
Fixed effects
Interceptchild	0.00 [0.00; 0.00]	1.34 [1.22; 1.46]	0.00 [0.00; 0.00]	0.00 [0.00; 0.00]	1.63 [1.48; 1.78]	0.00 [0.00; 0.00]
Slopechild	0.84 [0.64; 1.04]*	0.35 [0.26; 0.44]*	0.06 [−0.03;0.16]	0.63 [0.43; 0.80]*	0.16 [0.10; 0.23]*	0.04 [−0.04;0.11]
Random effects
Interceptchild	0.32 [0.13; 0.65]*	0.09 [0.02; 0.18]*	0.11 [0.05; 0.21]*	0.62 [0.37; 1.05]*	0.17 [0.08; 0.30]*	0.06 [0.02; 0.13]*
Slopechild	0.03 [0.00; 0.13]*	0.02 [0.00; 0.08]*	0.01 [0.00; 0.03]*	0.01 [0.00; 0.04]*	0.01 [0.00; 0.05]*	0.00 [0.00; 0.02]*
Interceptword	4.70 [2.79; 8,30]*	0.02 [0.01; 0.04]*	0.07 [0.04; 0.13]*	3.98 [2.40; 6.95]*	0.05 [0.03; 0.08]*	0.05 [0.02; 0.11]*
Slopeword	0.03 [0.00; 0.16]*	0.01 [0.00; 0.01]*	0.00 [0.00; 0.01]*	0.07 [0.00; 0.24]*	0.00 [0.00; 0.00]*	0.00 [0.00; 0.01]*
Interceptresidual	0.52 [0.13; 1,20]*	0.02 [0.01; 0.03]*	0.02 [0.00; 0.06]*	0.54 [0.21; 1.04]*	0.01 [0.01; 0.02]*	0.06 [0.03; 0.12]*
Sloperesidual	0.69 [0.30; 1,14]*	0.01 [0.01; 0.02]*	0.02 [0.00; 0.05]*	0.26 [0.07; 0.51]*	0.00 [0.00; 0.01]*	0.02 [0.00; 0.04]*
PPP	0.40	0.31	0.00	0.45	0.34	0.00
DIC	–	7,050.80	–	–	5,935.02	–
R2child	0.85	0.47	0.80	0.93	0.69	0.74
R2word	0.97	0.82	0.96	0.97	0.87	0.97
Number of words	40	40	40	40	40	40
Number of children	61	61	61	56	56	56
Number of observations	2,440	2,440	2,440	2,240	2,240	2,240
Number of parameters	17	20	66	17	20	66

R-square averaged across time points. PPP, posterior predictive p-value; DIC, deviance; BCI, Bayesian credibility interval.

^*p < 0.05.