# What Use Are Rasch Measures?

Question: I've spent a lot of time and effort estimating Rasch measures. Now what do I do with them?

Reply: Rasch measures can be used wherever person raw scores and percentages or item p-values would be used in conventional test reporting and statistical analysis. Rasch measures have the linear properties that most statistical routines (and non-specialist readers) assume of your numbers, but which raw scores and p-values don't have. So you can use Rasch measures for reports, plots, descriptive statistics, statistical tests, regressions, etc. A powerful use of Rasch measures is to draw pictures (item and person maps) which show the item hierarchy (the construct validity) of the items, and the person hierarchy (the predictive validity) of the persons.

The hierarchy of item difficulties is especially important because it defines what is being measured, the measurement ruler. Does the ordering of the items in difficulty match the intentions of the instrument developer and the expectations of those planning to use the test results? It is yet more instructive if, prior to data collection, the test development team sketch out the intended difficulty order of the items. This can then be compared with the order estimated from the data. The comparison usually confirms most of the intended ordering, so supporting the validity of the test. But the comparison may also point out an item or two that were supposed to be easy but are not, and vice-versa. This leads to a better understanding of the underlying construct, the latent variable, and also to improvement in the items. When an a supposedly easy item is reported to be difficult in practice, this can also indicate an area where better education or training is needed of those for whom the test or assessment is intended.

For instance, in the Knox Cube Test (a standard dataset, Wright & Stone, 1979), a gap in the item hierarchy indicates where new items should be written to target the sample. The item hierarchy also indicates how "number of taps", "number of reversals", and "length of sequences" affect item difficulty, so leading to a better understanding of how we store information in our short-term memory. Item difficulty measures are important if the instrument is to be used for setting criterion-level cut-points. They are also crucial for equating instruments, and for selecting items for adaptive administration.

What Use Are Rasch Measures? … Rasch Measurement Transactions, 2007, 21:2 p. 1104

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.

Coming Rasch-related Events
Aug. 5 - Aug. 6, 2024, Fri.-Fri. 2024 Inaugural Conference of the Society for the Study of Measurement (Berkeley, CA), Call for Proposals
Aug. 9 - Sept. 6, 2024, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
Oct. 4 - Nov. 8, 2024, Fri.-Fri. On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Jan. 17 - Feb. 21, 2025, Fri.-Fri. On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
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
Oct. 3 - Nov. 7, 2025, Fri.-Fri. On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com