Rasch analysis is one of the modern psychometric techniques that form part of Item Response Theory. Using specially designed software (RUMM2030) this technique provides a formal assessment of the measurement properties of scales. It also allows a linear transformation of ordinal scales to interval level measures, permitting the use of parametric statistical techniques and the calculation of change scores.
Rasch analysis is increasingly being used in the areas of health, medicine, psychology and business to develop and refine scales and tests. It provides detailed feedback on all aspects of the scale including the response format, the fit of the items, item bias, dimensionality and the spread of items across the trait being measured.
This course assumes previous experience or training in the general principles of scale development but assumes no previous experience with Rasch Analysis.
Topics
Introduction to measurement and testing
Theoretical frameworks – Comparison of Classical Test Theory (CTT) and Item Response Theory (IRT)
Preliminary item analysis and assessment of dimensionality using SPSS
Preparing the data file for Rasch analysis in RUMM2030
Evaluating overall model fit
Checking the response format (thresholds) and rescoring items
Detecting misfitting items and persons
Identifying item bias (Differential Item Functioning)
Assessing the dimensionality and targeting of a scale
Exporting Rasch scores to SPSS for other analyses
The course takes a practical applied approach (rather than mathematical) and participants are provided with detailed, hands-on experience.
• SPSS will be used for all preliminary item analysis and preparation of the data file.
• RUMM2030 is used for the Rasch analysis training and participants will be provided with a limited licence version of the software that they can take home to use on their own data.
Participants are encouraged to bring their own data, questionnaires etc to the course. Time is allocated during the course for participants to work on their own projects.
