Table 1.

Demographic information and standardized test scores by participant group

Measure	SLI-VM Comparison		VM Mean (SD)	SLI Mean (SD)	AM Mean (SD)	SLI-AM Comparison
	p	t (31)				t (31)	p
Age (months)	.006	2.95	66 (19)	82 (11.8)	82 (12.1)	<1	.995
SPELT	<.0001	−7.70	105 (12.43)	73 (10.16)	111 (9.27)	−11.06	<.0001
TNL-NLAI	.0007	−3.93	108a (10.19)	84 (16.27)	108 (11.17)	−5.04	<.0001
NEPSY-NWR	<.0001	−6.42	11.45a (2.25)	6.81 (1.5)	12.06 (1.6)	−9.66	<.0001
EVT	.0005	−3.92	105 (13.37)	88 (11.73)	110 (8.50)	−6.27	<.0001
PPVT	<.0001	−5.41	117 (11.14)	96 (10.58)	113 (10.75)	−4.31	.0002
Mat. ed. (years)	.0004	−4.00	17 (2.1)	14 (2.0)	16 (2.5)	−2.50	.02
KBIT-matrices	.01	−2.71	108 (12.79)	96 (12.19)	106 (11.94)	−2.22	.03

Note: SLI, specific language impairment; VM, vocabulary mate; AM, age mate; SPELT, Structured Photographic Expressive Language Test; TNL-NLAI, Test of Narrative Language—Narrative Language Ability Index; NEPSY-NWR, NEPSY—Nonword repetition subtest; EVT, Expressive Vocabulary Test; PPVT, Peabody Picture Vocabulary Test (3rd ed.); Mat. ed., maternal education; KBIT-matrices, Kaufman Brief Intelligence Test—Matrices subtest. The comparison of the SLI and VM groups proceeds from the middle to the left, and the comparison of the SLI and AM groups proceeds from the middle to the right. Unless indicated otherwise, all measures are reported as standard scores as determined by the scoring procedures and normative data reported in the test manuals.

^aThe standard scores on the TNL-NLAI and the NEPSY-NWR are based on 9 and 11 children, respectively, because only these children were old enough to take the tests.