Table 2.

χ²-statistics from DIF analysis for Comparisons I: focal = non-hearing impaired; II: focal = hearing aid group; III: focal=hearing aid group, reference=hearing impaired, no aid.

		item	Comparison I		anchor	Comparison II		anchor	Comparison III		anchor
			IRTLR	OLR		IRTLR	OLR		IRTLR	OLR
Aid stigma
	non-uniform	as1	8.1*	2.1	12.1 *	14.9*	12.5*	10.5*	3.6	0.5	3.0
		as2	4.8	0.7		4.7	1.2		0.7	0.1
		as3	2.7	0.4	0	0.4	8.3*	3.2	2.1	12.4*	1.1
		as4	0.5	2.2		1.0	3.8		3.3	4.7
		as5	3.6	0.9		6.9	2.4		1.0	0.1
		as6	0	0.5		0.8	0.3		1.0	0.1
	uniform	as2	7.4*	5.0	7.4*1	7.0	4.2	7.0*1	2.0	0.9	2.0
		as3	0.2	4.4		1.2	4.0		1.7	3.4
		as4	0	0		0.3	1.2		1.5	3.4
		as5	0	1.1		0	2.5		1.8	0.6
		as6	0.3	0.1		0.6	0.1		0.2	1.1
Pressure
	non-uniform	p2	0.3	0.1		0	0		1.2	0
		p3	5.0	7.0*	5.0	0.4	17.8*	0.4	0.2	7.5*	0.2
		p4	3.0	0.1		1.3	1.0		0	2.4
		p6	2.7	4.5		0	0.3		0.1	0
		p7	0	2.3		0.8	0.1		2.2	0.7
	uniform	p2	0.3	0.5		0.6	0		0.8	0
		p3	9.9*	11.4*	9.9*	2.2	6.8	2.2	2.2	5.0	2.2
		p4	2.9	4.0		2.7	2.3		1.6	1.3
		p6	2.7	0.1		0.7	0.6		0.2	0
		P7	0.2	1.1		0.6	0.1		0.8	0
Aid unwanted
	non-uniform	au1	4.7	1.7		1.7	0		0.2	0
		au2	0.2	2.5		0.9	2.6		2.1	2.0
		au3	0.3	4.8		0	0		1.2	0
		au4	0	0.1		0.1	2.4		2.7	4.4
		au5	0.6	1.3		2.7	1.6		0.7	4.9
	uniform	au1	4.7	0.7	5.3	14.4*	11.4*	13.0*	8.3	5.7	6.8
		au2	0	5.3	0	2.8	7.0*	3.7	2.7	2.9	2.6
		au3	0.6	0.1		1.0	5.9		3.1	0.7
		au4	1.8	2.6		3.0	2.4		3.7	1.1
		au5	2.7	0.1		1.3	2.9		3.3	0.9

*Indicates significance at .05 after Bonferroni correction; df=1, for non-uniform IRTLR and all OLR comparisons; df=2, for uniform IRTLR comparisons, 1 indicates 1 df for uniform DIF occurring when 0 counts for a response category for one of the groups considered.