A Step-by-Step Guide for Assessing DIF Using the Rasch Model
Abstract
Fairness is a fundamental aspect of validity and a core ethical principle in counseling, yet remains understudied as a measurement property in counseling research. Differential item functioning (DIF) analysis within the Rasch model offers a robust approach for assessing issues of fairness by evaluating test items for potential bias. This article provides a step-by-step guide for counseling researchers to assess DIF using the Rating Scale Model (RSM) in Winsteps. We outline procedures for evaluating model requirements and fit and identifying DIF using both statistical and graphical approaches. We present an applied example using CES-D data to demonstrate implementation and interpretation.
Fields of Study & Subjects
Psychometric Methodologies and Testing
Occupational Therapy Practice and Research
Psychological Testing and Assessment
Publication details
- Journal / source
- Measurement and Evaluation in Counseling and Development
- Publisher
- Informa UK Limited
- Volume
- 59
- Issue
- 2
- Pages
- 176–193
- Publication date
- 26 March 2026
- Language
- EN