THE RASCH METHOD OF ITEM ANALYSIS ADVANCES IN ITEM AND TEST DEVELOPMENT

Abstract

The purpose of this article is to recast the Rasch method of item and test development in both theoretical and practical forms to broaden insights into the model’s applicability in everyday work and research. The Rasch model tries to describe what happens when an examinee with certain ability encounters a question with a certain difficulty level. Following some assumptions, it states in a probabilistic manner the way people and questions relate. The process contrasts sharply with the most widely used item analysis techniques, which simply report total scores on people and on questions and item total score correlation coefficient as the means of describing test response data. The Rasch method uses two pieces of information: item and person parameters. With the help of the computer these parameters are calibrated and indexed. From this a scale free from a particular population of students will be created which will enable the user to interpret level of performance directly with respect to the curriculum.