| Raw Scores Are Not Linear Measures: : Rasch vs. Classical Test Theory CTT Comparison | ||
|---|---|---|
| Standing | Raw Scores | Linear Measures |
| Psychometrics | Classical Test Theory CTT | Rasch Model RM |
| Data | must be "complete" | robust against missing data and non-administered items |
| Meaning | ordinal ranking on hoped-for latent variable | linear positioning on latent variable explicitly-defined by item content |
| Status | mistaken for truth | known as estimates |
| Additivity | non-linear, bent | linear, straight |
| Continuity | discrete, lumpy | continuous, smooth |
| Precision | unknown, except on average | quantified by standard errors |
| Accuracy | unknown | quantified by local fit statistics |
| Linear Analysis | unsuited to usual statistics | ideal for usual statistics |
| Validity | sample-dependent test "reliability" | item-dependent construct validity |
| Diagnosis | sample-dependent item point-biserial | individual item and person fit statistics |
| Conceptualization | concrete | abstract |
| Occurrence | accidental | deliberate |
| Construction | irreproducible | reproducible |
| Scope | local | general |
| Relationships | incomparable | comparable |
| Context | test-bound | test-free |
| Integration | awkward to equate | simple to equate |
| Benjamin D. Wright | ||
Raw Scores Are Not Linear Measures: : Rasch vs. Classical Test Theory CTT Comparison. B.D. Wright … Rasch Measurement Transactions, 1992, 6:1, 208
Please help with Standard Dataset 4: Andrich Rating Scale Model
| Rasch Publications | ||||
|---|---|---|---|---|
| Rasch Measurement Transactions (free, online) | Rasch Measurement research papers (free, online) | Probabilistic Models for Some Intelligence and Attainment Tests, Georg Rasch | Applying the Rasch Model 3rd. Ed., Bond & Fox | Best Test Design, Wright & Stone |
| Rating Scale Analysis, Wright & Masters | Introduction to Rasch Measurement, E. Smith & R. Smith | Introduction to Many-Facet Rasch Measurement, Thomas Eckes | Invariant Measurement: Using Rasch Models in the Social, Behavioral, and Health Sciences, George Engelhard, Jr. | Statistical Analyses for Language Testers, Rita Green |
| Rasch Models: Foundations, Recent Developments, and Applications, Fischer & Molenaar | Journal of Applied Measurement | Rasch models for measurement, David Andrich | Constructing Measures, Mark Wilson | Rasch Analysis in the Human Sciences, Boone, Stave, Yale |
| in Spanish: | Análisis de Rasch para todos, Agustín Tristán | Mediciones, Posicionamientos y Diagnósticos Competitivos, Juan Ramón Oreja Rodríguez | ||
| Forum | Rasch Measurement Forum to discuss any Rasch-related topic |
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| July 31 - Aug. 3, 2017, Mon.-Thurs. | Joint IMEKO TC1-TC7-TC13 Symposium 2017: Measurement Science challenges in Natural and Social Sciences, Rio de Janeiro, Brazil, imeko-tc7-rio.org.br |
| Aug. 7-9, 2017, Mon-Wed. | In-person workshop and research coloquium: Effect size of family and school indexes in writing competence using TERCE data (C. Pardo, A. Atorressi, Winsteps), Bariloche Argentina. Carlos Pardo, Universidad Catòlica de Colombia |
| Aug. 7-9, 2017, Mon-Wed. | PROMS 2017: Pacific Rim Objective Measurement Symposium, Sabah, Borneo, Malaysia, proms.promsociety.org/2017/ |
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| Aug. 11 - Sept. 8, 2017, Fri.-Fri. | On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com |
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| Oct. 13 - Nov. 10, 2017, Fri.-Fri. | On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
| Jan. 5 - Feb. 2, 2018, Fri.-Fri. | On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
| Jan. 10-16, 2018, Wed.-Tues. | In-person workshop: Advanced Course in Rasch Measurement Theory and the application of RUMM2030, Perth, Australia (D. Andrich), Announcement |
| Jan. 17-19, 2018, Wed.-Fri. | Rasch Conference: Seventh International Conference on Probabilistic Models for Measurement, Matilda Bay Club, Perth, Australia, Website |
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| May 25 - June 22, 2018, Fri.-Fri. | On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
| June 29 - July 27, 2018, Fri.-Fri. | On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com |
| Aug. 10 - Sept. 7, 2018, Fri.-Fri. | On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com |
| Oct. 12 - Nov. 9, 2018, Fri.-Fri. | On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
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