Random number generator

For generating pseudo-random numbers, used in simulating data, Winsteps implements a FORTRAN 77 adaptation of this "Mersenne Twister" code:


c  A C-program for MT19937, with initialization improved 2002/1/26.

c  Coded by Takuji Nishimura and Makoto Matsumoto.

c  Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,

c  All rights reserved.

c  Copyright (C) 2005, Mutsuo Saito,

c  All rights reserved.


Their website is www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html


The generator is seeded with the system time or a value chosen by the analyst.


Simulated data observations.


Winsteps simulates data using the estimated values of person ability, item difficulty and rating-scale thresholds. Winsteps implements www.rasch.org/rmt/rmt213a.htm for dichotomous and polytomous data.


If you use these simulated data to estimate the parameter values, then the estimated values will be somewhat wider than the generators. This is due to JMLE bias. It can usually be corrected with STBIAS=YES.

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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
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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
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