IRT and Confusion about Rasch Measurement

The International Journal of Educational and Psychological Assessment contains papers relating to Classical Test Theory (CTT), Item Response Theory (IRT) and Rasch measurement. Unfortunately these papers present a confusing perspective on Rasch measurement. For instance,

1. Cutoff Scores: The Basic Angoff Method and the Item Response Theory Method. Niclie Tiratira. tijepa.books.officelive.com/Documents/article5v1.pdf

This articles employs Bigsteps and Winsteps, without citing the sources, in an IRT context, and reports results with no sense of the fingernails-on-the-blackboard dissonance infit and outfit have relative to IRT.

2. The Measurement of Change in Groups and Individuals With Particular Reference to the Value of Change Scores: A New IRT-Based Methodology for the Assessment of Treatment Effects. Jörg A. Prieler and John Raven. tijepa.books.officelive.com/Documents/A3V3_TIJEPA.pdf

This article asks and answers the following questions:

Question 1. Does the portrayal of parallel item characteristic curves (ICCs) in Rasch computer analysis output mislead many into thinking the item difficulty order is independent of ability?
Their answer: Yes. But the Rasch answer: No. Rasch analysis deliberately constructs item difficulties which are as independent as statistically possible of ability.

Question 2. Do the crossing ICCs in a 3-parameter IRT analysis indicate that the appropriate model for these data is one that describes the interactions making item and person estimates dependent on one another?
Their answer: Yes. But the Rasch answer: No. Crossing ICCs are never an appropriate model (except for some polytomous models.) Construct validity demands that the item difficulty hierarchy is invariant across person abilities.

Question 3: Are the "most popular versions of Item Response Theory" often loosely referred to as "the Rasch model"?
Their answer: Yes. But the Rasch answer: No. IRT is a descriptive statistical methodology originated by Frederic Lord. Rasch analysis is a prescriptive measurement methodology originated by Georg Rasch. One of Lord's IRT models resembles a Rasch model.

Comment: What chaos! The force of the academically-dominant IRT paradigm's influence is truly impressive: it is able to make people see things that don't exist, and to let them ignore existing things that don't fit with their preconceptions. How will these kinds of misconceptions ever be corrected? Will it all come out in the wash at some point down the road when invariance, sufficiency and additivity are demanded as basic elements of credible psychometric measurement?

William P. Fisher, Jr.

IRT and Confusion about Rasch Measurement, W.P. Fisher, Jr. ... Rasch Measurement Transactions, 2010, 24:2 p. 1288

Rasch-Related Resources: Rasch Measurement YouTube Channel
Rasch Measurement Transactions & Rasch Measurement research papers - free	An Introduction to the Rasch Model with Examples in R (eRm, etc.), Debelak, Strobl, Zeigenfuse	Rasch Measurement Theory Analysis in R, Wind, Hua	Applying the Rasch Model in Social Sciences Using R, Lamprianou	El modelo métrico de Rasch: Fundamentación, implementación e interpretación de la medida en ciencias sociales (Spanish Edition), Manuel González-Montesinos M.
Rasch Models: Foundations, Recent Developments, and Applications, Fischer & Molenaar	Probabilistic Models for Some Intelligence and Attainment Tests, Georg Rasch	Rasch Models for Measurement, David Andrich	Constructing Measures, Mark Wilson	Best Test Design - free, Wright & Stone Rating Scale Analysis - free, Wright & Masters
Virtual Standard Setting: Setting Cut Scores, Charalambos Kollias	Diseño de Mejores Pruebas - free, Spanish Best Test Design	A Course in Rasch Measurement Theory, Andrich, Marais	Rasch Models in Health, Christensen, Kreiner, Mesba	Multivariate and Mixture Distribution Rasch Models, von Davier, Carstensen
Rasch Books and Publications: Winsteps and Facets
Applying the Rasch Model (Winsteps, Facets) 4th Ed., Bond, Yan, Heene	Advances in Rasch Analyses in the Human Sciences (Winsteps, Facets) 1st Ed., Boone, Staver	Advances in Applications of Rasch Measurement in Science Education, X. Liu & W. J. Boone	Rasch Analysis in the Human Sciences (Winsteps) Boone, Staver, Yale	Appliquer le modèle de Rasch: Défis et pistes de solution (Winsteps) E. Dionne, S. Béland
Introduction to Many-Facet Rasch Measurement (Facets), Thomas Eckes	Rasch Models for Solving Measurement Problems (Facets), George Engelhard, Jr. & Jue Wang	Statistical Analyses for Language Testers (Facets), Rita Green	Invariant Measurement with Raters and Rating Scales: Rasch Models for Rater-Mediated Assessments (Facets), George Engelhard, Jr. & Stefanie Wind	Aplicação do Modelo de Rasch (Português), de Bond, Trevor G., Fox, Christine M
Exploring Rating Scale Functioning for Survey Research (R, Facets), Stefanie Wind	Rasch Measurement: Applications, Khine	Winsteps Tutorials - free Facets Tutorials - free	Many-Facet Rasch Measurement (Facets) - free, J.M. Linacre	Fairness, Justice and Language Assessment (Winsteps, Facets), McNamara, Knoch, Fan

Forum

Rasch Measurement Forum to discuss any Rasch-related topic

Go to Top of Page
Go to index of all Rasch Measurement Transactions
AERA members: Join the Rasch Measurement SIG and receive the printed version of RMT
Some back issues of RMT are available as bound volumes
Subscribe to Journal of Applied Measurement

Go to Institute for Objective Measurement Home Page. The Rasch Measurement SIG (AERA) thanks the Institute for Objective Measurement for inviting the publication of Rasch Measurement Transactions on the Institute's website, www.rasch.org.

The URL of this page is www.rasch.org/rmt/rmt242e.htm

Website: www.rasch.org/rmt/contents.htm