Assessing differential functioning in a satisfaction scale.
In this study, an item response theory-based differential functioning of items and tests (DFIT) framework (N. S. Raju, W. J. van der Linden, & P. F. Fleer, 1995) was applied to a Likert-type scale. Several differential item functioning (DIF) analyses compared the item characteristics of a 10-item satisfaction scale for Black and White examinees and for female and male examinees. F. M. Lord's (1980) chi-square and the extended signed area (SA) measures were also used. The results showed that the DFIT indices consistently performed in the expected manner. The results from Lord's chi-square and the SA procedures were somewhat varied across comparisons. A discussion of these results along with an illustration of an item with significant DIF and suggestions for future DIF research are presented.
Collins
W C
WC
Institute of Psychology, Illinois Institute of Technology, Chicago 60616-3793, USA.
Raju
N S
NS
Edwards
J E
JE
D001741:Black or African American / Q000523:psychology; D003431:Cross-Cultural Comparison; D005260:Female; D006801:Humans; D007588:Job Satisfaction; D008297:Male; D008889:Military Personnel / Q000523:psychology; D011594:Psychometrics / Q000379:methods*; D012737:Sex Factors; D014481:United States; D044465:White People / Q000523:psychology