title: Using the cumulative common log-odds ratio to identify differential item functioning of rating scale items in the exercise and sport sciences.
abstract: One aspect of construct validity is the extent to which the measurement properties of a rating scale are invariant across the groups being compared. An increasingly used method for assessing between-group differences in the measurement properties of items of a scale is the framework of differential item functioning (DIF). In this paper we introduce the concept of DIF as a validation tool for scales used in physical education and exercise science, and illustrate the use of the cumulative common log-odds ratio for assessing the presence of DIF with data from the Exercise Imagery Inventory (EII; Giacobbi, Hausenblas, & Penfield, 2005).
authors.affiliation: Department of Educational and Psychological Studies, University of Miami, Coral Gables, FL 33124-2040, USA. penfield@miami.edu
authors.forename: Randall D
authors.initials: RD
authors.lastname: Penfield
authors.forename: Peter R
authors.initials: PR
authors.lastname: Giacobbi
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Myers
mesh_terms: D001294:Attitude to Health; D003627:Data Interpretation, Statistical; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D016017:Odds Ratio; D011594:Psychometrics / Q000706:statistics & numerical data*; D012107:Research Design; D013177:Sports