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. 2016 May 25;77(4):545–569. doi: 10.1177/0013164416651116

Table 2.

Item Parameters Used in the Generating DIF Conditions for the Last Two or Four Items.

Focal group
Reference group
 Low DIF
 Medium DIF
Condition Test length Item a 1 a 2 d a 1 a 2 d a 1 a 2 d
Uniform DIF (U-A) 12 11 1.0 0.1 0.0 1.0 0.1 0.25 1.0 0.1 0.5
12 0.1 1.0 0.0 0.1 1.0 0.25 0.1 1.0 0.5
14 11 1.0 0.1 0.0 1.0 0.1 0.25 1.0 0.1 0.5
12 0.1 1.0 0.0 0.1 1.0 0.25 0.1 1.0 0.5
13 0.7 0.7 0.0 0.7 0.7 0.25 0.7 0.7 0.5
14 0.7 0.7 0.0 0.7 0.7 0.25 0.7 0.7 0.5
24 21 1.0 0.1 0.0 1.0 0.1 0.25 1.0 0.1 0.5
22 0.1 1.0 0.0 0.1 1.0 0.25 0.1 1.0 0.5
23 0.7 0.7 0.0 0.7 0.7 0.25 0.7 0.7 0.5
24 0.7 0.7 0.0 0.7 0.7 0.25 0.7 0.7 0.5
Nonuniform DIF (N-B) 12 11 1.0 0.1 0.0 1.0 0.4 0.25 1.0 0.7 0.5
12 0.1 1.0 0.0 0.1 1.3 0.00 0.1 1.6 0.0
14 11 1.0 0.1 0.0 1.0 0.4 0.25 1.0 0.7 0.5
12 0.1 1.0 0.0 0.1 1.3 0.25 0.1 1.6 0.5
13 0.7 0.7 0.0 0.7 1.0 0.25 0.7 1.3 0.5
14 0.7 0.7 0.0 0.7 1.0 0.00 0.7 1.3 0.0
24 21 1.0 0.1 0.0 1.0 0.4 0.25 1.0 0.7 0.5
22 0.1 1.0 0.0 0.1 1.3 0.25 0.1 1.6 0.5
23 0.7 0.7 0.0 0.7 1.0 0.25 0.7 1.3 0.5
24 0.7 0.7 0.0 0.7 1.0 0.00 0.7 1.3 0.0
Nonuniform DIF (N-C) 12 11 1.0 0.1 0.0 1.3 0.4 0.25 1.6 0.7 0.5
12 0.1 1.0 0.0 0.4 1.3 0.00 0.7 1.6 0.0
14 11 1.0 0.1 0.0 1.3 0.4 0.25 1.6 0.7 0.5
12 0.1 1.0 0.0 0.4 1.3 0.25 0.7 1.6 0.5
13 0.7 0.7 0.0 1.0 1.0 0.25 1.3 1.3 0.5
14 0.7 0.7 0.0 1.0 1.0 0.00 1.3 1.3 0.0
24 21 1.0 0.1 0.0 1.3 0.4 0.25 1.6 0.7 0.5
22 0.1 1.0 0.0 0.4 1.3 0.25 0.7 1.6 0.5
23 0.7 0.7 0.0 1.0 1.0 0.25 1.3 1.3 0.5
24 0.7 0.7 0.0 1.0 1.0 0.00 1.3 1.3 0.0