Diagnosing Misfit

------------------------------------------------------------------
Classification  INFIT  OUTFIT  Explanation  Investigation
------------------------------------------------------------------
Hard Item       Noisy  Noisy   Bad item     Ambiguous or
                                            negative wording?
                                            Debatable or
                                            misleading options?
                Muted  Muted   Only answered by top people
                                            At end of test?
------------------------------------------------------------------
Item            Noisy  Noisy   Qualitatively different item
                               Incompatible anchor value
                                            Different process
                                            or content?
                                            Anchor value
                                            incorrectly applied?
                        ?       Biased (DIF) item
                                Stratify residuals by person group?
                        Muted   Curriculum interaction
                                            Are there alternative
                                            curricula?
------------------------------------------------------------------
                Muted   ?       Redundant item
                                            Similar items?
                                            One item answers another?
                                            Item correlated
                                            with other variable?
------------------------------------------------------------------
Rating scale    Noisy   Noisy   Extreme category overuse
                Muted   Muted   Middle category overuse
                                       Poor category wording?
                                       Combine or omit categories?
                                       Wrong model for scale?
------------------------------------------------------------------
Person          Noisy   ?        Processing error
                                 Clerical error
                                 Idiosyncratic person
                                       Scanner failure?
                                       Form markings misaligned?
                                    Qualitatively different person?
------------------------------------------------------------------
High Person     ?       Noisy    Careless
                                 Sleeping
                                 Rushing
                                       Unexpected wrong answers?
                                       Unexpected errors at start?
                                       Unexpected errors at end?
------------------------------------------------------------------
Low Person      ?      Noisy    Guessing
                                Response set
                                "Special" knowledge
                                       Unexpected right answers?
                                       Systematic response pattern?
                                       Content of unexpected answers?
                Muted  ?        Plodding
                                Caution
                                       Did not reach end of test?
                                       Only answered easy items?
------------------------------------------------------------------
Person/
Judge Rating    Noisy  Noisy    Extreme category overuse
                                       Extremism? Defiance?
                Muted  Muted    Middle category overuse
                                       Conservatism? Resistance?
------------------------------------------------------------------
Judge Rating    Muted  Muted    Apparent unanimity
                                       Collusion?
------------------------------------------------------------------
INFIT: information-weighted mean-square, sensitive to irregular inlying patterns
OUTFIT: usual unweighted mean-square, sensitive to unexpected rare extremes
Muted: unmodelled dependence, redundance, error trends
Noisy: unexpected unrelated irregularities

See Wright & Stone, Best Test Design, p. 2-4, 66-82, 23-24, 121-125, 165-190, and Wright & Masters, Rating Scale Analysis, p. 19-23, 94- 105, 108-111 for basics, and 132-135, 147-151, 171-178, 190-198 for examples.


Diagnosing Misfit, B Wright … Rasch Measurement Transactions, 1991, 5:2 p. 156



Rasch Books and Publications
Invariant Measurement: Using Rasch Models in the Social, Behavioral, and Health Sciences, 2nd Edn. George Engelhard, Jr. & Jue Wang 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
Introduction to Many-Facet Rasch Measurement (Facets), Thomas Eckes 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 Appliquer le modèle de Rasch: Défis et pistes de solution (Winsteps) E. Dionne, S. Béland
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
Other 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

To be emailed about new material on www.rasch.org
please enter your email address here:

I want to Subscribe: & click below
I want to Unsubscribe: & click below

Please set your SPAM filter to accept emails from Rasch.org

Rasch Measurement Transactions welcomes your comments:

Your email address (if you want us to reply):

If Rasch.org does not reply, please post your message on the Rasch Forum
 

ForumRasch 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.

Coming Rasch-related Events
Apr. 21 - 22, 2025, Mon.-Tue. International Objective Measurement Workshop (IOMW) - Boulder, CO, www.iomw.net
Jan. 17 - Feb. 21, 2025, Fri.-Fri. On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Feb. - June, 2025 On-line course: Introduction to Classical Test and Rasch Measurement Theories (D. Andrich, I. Marais, RUMM2030), University of Western Australia
Feb. - June, 2025 On-line course: Advanced Course in Rasch Measurement Theory (D. Andrich, I. Marais, RUMM2030), University of Western Australia
May 16 - June 20, 2025, Fri.-Fri. On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
June 20 - July 18, 2025, Fri.-Fri. On-line workshop: Rasch Measurement - Further Topics (E. Smith, Facets), www.statistics.com
July 21 - 23, 2025, Mon.-Wed. Pacific Rim Objective Measurement Symposium (PROMS) 2025, www.proms2025.com
Oct. 3 - Nov. 7, 2025, Fri.-Fri. On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com

 

The URL of this page is www.rasch.org/rmt/rmt52k.htm

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