Table 4.

Rasch-Based Analysis of Words Understood Using the Differential Item Functioning Procedure.

	HR ASD		Non-ASD Comparison
Word	Ability†	Ability SE	Group	Ability	Ability SE	Ability Contrast††	More Likely for…	Rasch-Welch t
baabaa	−2.84	.42	LR	−1.69	.22	1.15	HR ASD	2.42**
pig	−1.84	.49	LR	.00	.32	1.84	HR ASD	3.13**
bubbles	−2.48	.44	LR	−1.43	.23	1.05	HR ASD	2.11*
coat	−.96	.61	LR	1.50	.54	2.46	HR ASD	3.01**
playpen	.02	.82	LR	2.29	.74	2.27	HR ASD	2.05*
blanket	−3.18	.41	LR	−1.94	.22	1.25	HR ASD	2.70*
watch	−.54	.69	LR	1.50	.54	2.04	HR ASD	2.32*
brother	−4.28	.39	LR	−2.26	.21	2.02	HR ASD	4.53**
child	.02	.82	LR	3.01	.98	2.99	HR ASD	2.3*
out	−1.30	.56	LR	.35	.36	1.65	HR ASD	2.49**
open	−2.07	.47	LR	−.83	.26	1.24	HR ASD	2.31*
t-brush	−1.38	.23	LR	.92	1.11	−2.29	LR	−2.02*
cheerio	−3.51	1.00	HR	−2.51	.20	.45	HR ASD	2.24*
boots	.02	.82	HR	4.15	1.72	4.13	HR ASD	2.16*
pants	−1.30	.56	HR	.03	.33	1.32	HR ASD	2.04*
hand	−2.07	.47	HR	−.90	.26	1.16	HR ASD	2.18*
S′ name	−1.84	.49	HR	−.37	.30	1.47	HR ASD	2.56**
child	.02	.82	HR	4.17	1.75	4.15	HR ASD	2.15*
open	−2.07	.47	HR	−.97	.25	1.10	HR ASD	2.06*
hungry	−2.48	.44	HR	−1.40	.23	1.07	HR ASD	2.16*

Note.

^†Ability level measured in logits, (DIF: differential item functioning). The more negative an ability estimate for a group the more likely it was for the specified group to understand the word. Only meaningful differences are shown DIF>1 and p < 0.05.

^††Ability contrasts calculated as HR ASD Ability minus comparison group Ability. Absolute values greater than one indicate large effect size (see appendix A).

^*Significant at p≤0.05,

^**p<0.01.