A Simulation Study to Assess the Effect of the Number of Response Categories on the Power of Ordinal Logistic Regression for Differential Item Functioning Analysis in Rating Scales

Table 2

The power of OLR model under different combinations when .

Conditions	Ratio	DIF = 0.5			DIF = 1
		1		0.77	0.81	0.84	1.00	1.00	1.00
	0.74		0.77	0.79	1.00	1.00	1.00
	0.66		0.66	0.69	1.00	1.00	1.00
2		0.78	0.79	0.83	1.00	1.00	1.00
		0.76	0.76	0.79	1.00	1.00	1.00
		0.66	0.69	0.69	1.00	1.00	1.00
3		0.53	0.50	0.60	1.00	1.00	1.00
		0.43	0.48	0.49	0.98	0.98	0.99
		0.38	0.39	0.41	0.96	0.95	0.97
4		0.89	0.87	0.90	1.00	1.00	1.00
		0.79	0.83	0.86	1.00	1.00	1.00
		0.73	0.75	0.79	1.00	1.00	1.00
5		0.79	0.73	0.78	1.00	1.00	1.00
		0.70	0.71	0.76	1.00	1.00	1.00
		0.63	0.63	0.66	1.00	1.00	1.00
6		0.87	0.87	0.88	1.00	1.00	1.00
		0.85	0.81	0.85	1.00	1.00	1.00
		0.76	0.75	0.79	1.00	1.00	1.00
7		0.76	0.71	0.78	1.00	1.00	1.00
		0.70	0.68	0.70	1.00	1.00	1.00
		0.67	0.61	0.63	1.00	1.00	1.00
8		0.78	0.71	0.77	1.00	1.00	1.00
		0.64	0.66	0.70	1.00	1.00	1.00
		0.57	0.53	0.57	1.00	1.00	1.00
9		0.35	0.32	0.34	0.96	0.96	0.98
		0.28	0.31	0.36	0.95	0.96	0.96
		0.27	0.29	0.32	0.89	0.89	0.94

: number of response categories.
: and , : and , and : and .
The conditions are described in Table 1.