Rasch Measurement Theory Analysis in R

Stefanie A. Wind is an Associate Professor of Educational Measurement at the University of Alabama. Her primary research interests include the exploration of methodological issues in the field of educational measurement, with emphases on methods related to rater-mediated assessments, rating scales, Rasch models, item response theory models, and nonparametric item response theory, as well as applications of these methods to substantive areas related to education.Cheng Hua is a Ph.D. candidate in Educational Measurement program at the University of Alabama. His primary research interests include Rasch Measurement theory, advanced regression models, Bayesian statistics, and visual learning tools (such as Mind Maps and Concept Maps). He enjoys applying his psychometric and statistical skills to address real-world research questions through interdisciplinary collaborations.

• 1 Introduction 2 Dichotomous Rasch Model 3 Evaluating the Quality of Measures 4 Rating Scale Model 5 Partial Credit Model 6 Many Facet Rasch Model 7 Basics of Differential Item Functioning

Over 60 years ago, Georg Rasch introduced a fundamentally new way of viewing measurement theory into the social sciences. His approach to invariant measurement provides the opportunity to achieve sample-free calibration of items and item-free measurement of persons. His research remains the gold standard for developing psychometrically sound assessments. Stefanie A. Wind and Cheng Hua introduce Rasch's fundamental ideas to students, researchers, and practitioners using readily available software in R that facilitates the quest for invariant measurement. ­-George Engelhard, University of Georgia