What can be reported to a CAT examinee? Raw scores are meaningless. Percentiles provide no substantive guidance on strengths and weaknesses. Even measures have little value without a context.
Instructionally useful diagnostic information can be given, however, by using a variation of KIDMAP output (Wright, Mead, and Ludlow, 1980). This is implemented in the IPARM program (Smith, 1991). This program performs item and person analysis at a higher level of detail than calibration programs. The "IPARMM" option creates detailed maps of examinee performance for fixed length or computer adaptive tests.
Abbreviated versions of two person maps are shown. The top of each map summarizes the person's test performance: raw score, number of items attempted, logit ability, and standard error of measurement. Conventionally, the center of the scale, 0.0, represents the average item difficulty for the bank of test items. In practice, logits are usually rescaled into positive integers for published reports.
The center section of each map shows item level performance. The items answered correctly are shown in the top half, those answered incorrectly in the bottom half. Items are identified by five character item names supplied by the user. Here, item names are textbook chapter numbers followed by objectives within chapters.
The band that separates the correct and incorrect responses indicates the person's ability estimate by "®" with a ±1 standard error band around that estimated ability indicated by "-".
The line of symbols beneath the ability estimate indicates the expected success rate for this examinee. The probabilities of correctly answering an item in the indicated ranges are: 80%-100%: "///", 65%-80%: "<lt;lt;", 35%-65%: "===", 20%-35%: ">gt;gt;", 0%-20%:"\\\". These symbols provide a frame of reference for the person's mastery of the material and for the consistency (fit) of the person's performance.
The histogram below the item section shows the performance of all persons taking the examination. Each "*" represents one person. This provides a normative interpretation of the measure.
In the first example, Person 1 has a low score, falling in the lower quartile of the class performance. The CAT test covered a wide range of item difficulties, from -4.0 to +2.0 logits. There were no surprising responses. The map of wrong responses shows what objectives this person missed and forms a guide for further study.
In the second example, Person 38 has a much higher ability estimate, third in the class. This test also covers a wide range of item difficulties, -3.0 to +3.0 logits. Here there are three unexpected incorrect responses to what should be easy items for this person. Person 38 had more than an 80 percent chance of answering items 02-33, 02-39, and 02-40 correctly. It seems that even this able examinee would benefit from further study of parts of Chapter 2!
Richard M. Smith 1994 RMT 8:1 p. 344-5
Smith RM (1991) IPARM Computer Program. Chicago: MESA Press
Wright BD, Mead RJ, Ludlow LH (1980) KIDMAP: Person-by-Item Interaction Mapping. MESA Memorandum #29. Chicago: MESA Press
Reporting candidate performance on computer-adaptive tests. Smith RM. Rasch Measurement Transactions, 1994, 8:1 p.344-5
Please help with Standard Dataset 4: Andrich Rating Scale Model
|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|
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|
|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/|
|Aug. 10, 2017, Thurs.||In-person Winsteps Training Workshop (M. Linacre, Winsteps), Sydney, Australia. www.winsteps.com/sydneyws.htm|
|Aug. 11 - Sept. 8, 2017, Fri.-Fri.||On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com|
|Aug. 18-21, 2017, Fri.-Mon.||IACAT 2017: International Association for Computerized Adaptive Testing, Niigata, Japan, iacat.org|
|Sept. 15-16, 2017, Fri.-Sat.||IOMC 2017: International Outcome Measurement Conference, Chicago, jampress.org/iomc2017.htm|
|Oct. 13 - Nov. 10, 2017, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com|
|Oct. 25-27, 2017, Wed.-Fri.||In-person workshop: Applying the Rasch Model hands-on introductory workshop, Melbourne, Australia (T. Bond, B&FSteps), Announcement|
|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|
|April 13-17, 2018, Fri.-Tues.||AERA, New York, NY, www.aera.net|
|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|
|The HTML to add "Coming Rasch-related Events" to your webpage is:|
The URL of this page is www.rasch.org/rmt/rmt81m.htm