the university of tehran english proficiency test (utept) is a high-stakes entrance examination taken by more than 10,000 master’s degree holders annually. the examinees’ scores have a significant influence on the final decisions concerning admission to the university of tehran ph.d. programs. as a test validation investigation, the present study, which is a bias detection research in nature, u...

This research used logistic regression to model item responses from a popular 360-for-development survey. The model used method of survey delivery and rater group to identify items that exhibited differential item functioning (DIF). The methods of survey delivery were pencil-and-paper and online by web page. The rater groups were self, boss, peer, and direct report. The sample consisted of 374 ...