Table 3.

Raw scores for all nonverbal and language measures, with effect sizes for between‐group contrasts

Language/nonverbal measure (maximum score)	Reliability	Language trajectory	Mean (SD)	Effect sizes (d) for group contrasts
				Resolving	Emerging	Persisting
Nonverbal IQa t1 (n/a)	.84d	TL	112.5 (14.5)	.86*	.77*	0.96*
		Resolving	100.5 (6.25)	–	0.14	0.53
		Emerging	101.71 (10.07)		–	0.23
		Persisting	98.92 (13.27)			–
Basic concepts t1 (18)	.90d	TL	16.03 (1.78)	2.03*	1.07*	2.75*
		Resolving	12.25 (2.80)	–	0.89	0.22
		Emerging	14.14 (1.80)		–	1.46*
		Persisting	10.20 (3.10)			–
Expressive vocabulary t1 (40)	.88d	TL	20.07 (5.36)	1.26*	0.93*	2.17*
		Resolving	13.25 (6.73)	–	0.40	0.39
		Emerging	15.24 (3.91)		–	1.46*
		Persisting	8.74 (4.81)			–
Receptive grammar t1 (22)	.77d	TL	14.18 (3.00)	2.59*	1.00*	1.98*
		Resolving	6.50 (2.80)	–	1.66*	0.73
		Emerging	11.19 (2.96)		–	0.95
		Persisting	7.98 (3.66)			–
Inflectional morphologyb t1 (n/a)	.87e	TL	74.30 (23.80)	1.46*	0.84*	2.04*
		Resolving	39.66 (24.82)	–	0.52	0.03
		Emerging	53.68 (29.45)		–	1.08
		Persisting	26.50 (22.00)			–
Expressive vocabulary t3 (54)	.91d	TL	31.04 (6.58)	1.00*	1.53*	2.14*
		Resolving	24.58 (4.91)	–	0.61	0.99*
		Emerging	21.05 (6.43)		–	0.62
		Persisting	17.29 (6.05)			–
Receptive grammar t3 (26)	.74d	TL	21. 97 (2.52)	0.72	1.27*	1.97*
		Resolving	20.17 (2.62)	–	0.49	0.82*
		Emerging	18.57 (3.75)		–	0.60
		Persisting	16.19 (4.13)			–
Inflectional morphologyb t3 (n/a)	.87e	TL	96.88 (6.60)	0.71	0.85	1.56*
		Resolving	92.04 (9.77)	–	0.19	0.53*
		Emerging	88.78 (20.83)		–	0.57*
		Persisting	73.90 (28.76)			–
Nonverbal IQc t5 (n/a)	.84e	TL	0.34 (0.76)	0.43	1.42*	1.55*
		Resolving	0.02 (0.55)	–	1.25	1.25*
		Emerging	−0.73 (0.63)		–	0.15
		Persisting	−0.82 (0.71)			–
Receptive vocabulary t5 (170)	.78d	TL	100.63 (11.44)	0.50	1.53*	1.73*
		Resolving	95.00 (9.32)	–	1.17*	1.27**
		Emerging	83.43 (10.59)		–	0.21
		Persisting	81.19 (10.63)			–
Expressive vocabulary t5 (70)	.87d	TL	49.06 (6.28)	0.85	2.31*	2.53*
		Resolving	43.04 (3.26)	–	1.61*	1.47*
		Emerging	34.57 (5.60)		–	0.35
		Persisting	32.33 (7.24)			–
Receptive grammar t5 (20)	.88f	TL	15.69 (2.22)	0.50	3.03*	2.85*
		Resolving	14.58 (2.02)	–	2.15*	1.98*
		Emerging	7.33 (3.30)		–	0.53
		Persisting	8.59 (3.18)			–
Expressive grammar t5 (56)	.76d	TL	40.01 (7.34)	0.48	1.73*	2.09*
		Resolving	36.50 (7.04)	–	1.26*	1.40*
		Emerging	27.29 (7.80)		–	0.38
		Persisting	24.19 (8.52)			–

^aPerformance IQ.

^bTotal percent correct.

^cComposite z score.

^dTest/retest reliability.

^eAverage test/retest reliability across two subtests.

^fInternal consistency.

*p < .05; **p < .01; ***p < .001.