CATREF= reference category for Table 2 = (item measure)

If a particular category corresponds to a criterion level of performance, choose that category for CATREF=.


Table 2, "most probable responses/scores", maps the items vertically and the most probable responses, expected scores, and Rasch-Thurstone thresholds (50% cumulative probabilities) horizontally. Generally, the vertical ordering is item difficulty measure. If, instead, a particular category is to be used as the reference for sorting, give its value as scored and recoded.


Special uses of CATREF= are:

CATREF=-3 for item entry order

CATREF=-2 for item measure order

CATREF=-1 for items measure order with ISGROUPS=

CATREF=0 for item measure order

CATREF=1...254 for item measure order based on this category.


Example 1: You have 4-point partial-credit items, entered in your data as A,B,C,D, and then scored as 1,2,3,4. You wish to list them based on the challenge of category C, rescored as 3,

  CODES =ABCD  ; original responses

  NEWSCORE=1234 ; rescored values

  RESCORE=2  ; rescore all


  CATREF=3  ; Table 2 reference category

  ISGROUPS=0  ; partial credit: one item per grouping

If, for an item, the category value "3" is eliminated from the analysis or is the bottom category, the nearest higher category is used for that item.


Example 2: You have 6 3-category items in Grouping 1, and 8 4-category items in Grouping 2. You wish to list them in Table 2.2 by measure within grouping, and then by measure overall.


  NI= 14

  ISGROUPS= 11111122222222


  2.2 0 0 0 -1  -1 ; means CATREF=-1

  2.2 0 0 0 0  ; last 0 means CATREF=0


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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 with Raters and Rating Scales: Rasch Models for Rater-Mediated Assessments, George Engelhard, Jr. & Stefanie Wind 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
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Coming Rasch-related Events
April 10-12, 2018, Tues.-Thurs. Rasch Conference: IOMW, New York, NY,
April 13-17, 2018, Fri.-Tues. AERA, New York, NY,
May 22 - 24, 2018, Tues.-Thur. EALTA 2018 pre-conference workshop (Introduction to Rasch measurement using WINSTEPS and FACETS, Thomas Eckes & Frank Weiss-Motz),
May 25 - June 22, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps),
June 27 - 29, 2018, Wed.-Fri. Measurement at the Crossroads: History, philosophy and sociology of measurement, Paris, France.,
June 29 - July 27, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps),
July 25 - July 27, 2018, Wed.-Fri. Pacific-Rim Objective Measurement Symposium (PROMS), (Preconference workshops July 23-24, 2018) Fudan University, Shanghai, China "Applying Rasch Measurement in Language Assessment and across the Human Sciences"
Aug. 10 - Sept. 7, 2018, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets),
Sept. 3 - 6, 2018, Mon.-Thurs. IMEKO World Congress, Belfast, Northern Ireland
Oct. 12 - Nov. 9, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps),



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