PVALUE= proportion correct or average rating = No

An important statistic in classical item analysis is the item proportion-correct (item-analysis p-value), the proportion of the sample succeeding on a dichotomous item. In Winsteps, this value is interpreted as the average of the responses to the item for both dichotomous and polytomous items.


This proportion-correct-value is not a hypothesis test probability-value (statistical p-value). For hypothesis tests of fit, use the ZSTD values, which are probability-values expressed as unit-normal deviates.


PVALUE = NO Do not report the item observed proportion-correct-value.


PVALUE=YES Report item obsered proportion-correct-values in Tables 6, 10, etc. and IFILE= (over-riding the existing default setting.)


Example: To parallel a classical analysis of an MCQ data set, it is desired to report the raw scores (including extreme persons and items), the point-biserials and the proportion-correct-values or average ratings.

 TOTALSCORE= YES ; report original total raw scores

 PTBISERIAL = YES  ; report point-biserial, not point-measure correlations

 PVALUE = YES  ; report proportion-correct-values



|ENTRY   TOTAL                       |   INFIT  |  OUTFIT  |PTBSE|PROP-|                 |



|     1     35     35   -6.59    1.85| MINIMUM ESTIMATED MEASURE | 1.00| 1= 1-4          |

|     4     32     35   -4.40     .81| .90    .0| .35    .8|  .48|  .91| 4= 1-3-4        |

|    12      6     35    2.24     .55|1.16    .6|1.06    .5|  .26|  .17| 12=1-3-2-4-3    |

|    18      0     35    6.13    1.84| MAXIMUM ESTIMATED MEASURE |  .00| 18=4-1-3-4-2-1-4|

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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, www.iomw.org
April 13-17, 2018, Fri.-Tues. AERA, New York, NY, www.aera.net
May 22 - 24, 2018, Tues.-Thur. EALTA 2018 pre-conference workshop (Introduction to Rasch measurement using WINSTEPS and FACETS, Thomas Eckes & Frank Weiss-Motz), https://ealta2018.testdaf.de
May 25 - June 22, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
June 27 - 29, 2018, Wed.-Fri. Measurement at the Crossroads: History, philosophy and sociology of measurement, Paris, France., https://measurement2018.sciencesconf.org
June 29 - July 27, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com
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" www.promsociety.org
Aug. 10 - Sept. 7, 2018, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
Sept. 3 - 6, 2018, Mon.-Thurs. IMEKO World Congress, Belfast, Northern Ireland www.imeko2018.org
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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