Question: What assumptions are made about distributions by the Rasch model?
Answer: The Rasch model makes no assumptions about the distributions of the parameters. Maximum Likelihood Estimation (MLE) assumes that the randomness in the data is normally distributed. Some estimation methods, such as Marginal Maximum Likelihood (MMLE), assume that the incidental parameters (usually persons) conform to a well-behaved distribution (usually normal).
In the realm of scientific creativity ...
"Quality is a probabilistic function of quantity."
Simonton, D. (2003), Scientific Creativity as Constrained Stochastic Behavior: The Integration of Product, Person and Process Perspectives. Psychological Bulletin, 129(4), 475-494.
ACER ConQuest 3.0 is software for fitting unidimensional and multidimensional item response and latent regression models. It provides data analysis based on item response models (IRM), allowing examination of the properties of performance assessments, traditional assessments and rating scales. ConQuest 3.0 offers analysis procedures based on multifaceted item response models, multidimensional item response models, latent regression models and drawing plausible values.
New Features include:
Ray Adams, Margaret Wu and Mark Wilson
The 2nd Annual Ohio River Valley Objective Measurement Seminar (ORVOMS) was held on May 18th, 2012 at the University of Kentucky. It was hosted by Dr. Kelly Bradley of the Department of Educational Policy Studies & Evaluation and co-sponsored by Dr. Arne Bathke of the Applied Statistics Laboratory. The keynote speaker was Dr. Richard Smith from Data Recognition Corporation. In addition to the regional attendees some participants traveled from as far away as Florida, Michigan, and Minnesota.
We thank everyone who participated and presented this year - it was an interesting and collegial meeting. We look forward to next year’s seminar and hope that you will be able to participate. For information about upcoming events or to be placed on our mailing list please contact:
Psychometric Research Associate
The American Board of Family Medicine
mlybarger ~ theabfm.org
UK Rasch User Group, /www.rasch.org.uk
Richard M. Smith, Editor, www.jampress.org
Notes and Quotes, Rasch Measurement Transactions, 2012, 26:1, passim
|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 2nd. 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|
|Forum||Rasch Measurement Forum to discuss any Rasch-related topic|
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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|
|April 26, 2014, Sat.||Submission deadline: PROMS2014, Guangzhou, China: Aug. 2-6, 2014, Sat.-Wed., www.confchina.com|
|May 2, 2014, Fri.||ORVMS: Ohio River Valley Objective Measurement Seminar, Cincinnati OH, Announcement|
|May 14-16, 2014, Wed.-Fri.||In-person workshop: Introductory Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric|
|May 19-21, 2014, Mon.-Wed.||In-person workshop: Intermediate Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric|
|May 30 - June 27, 2014, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com|
|July 4 - Aug. 1, 2014, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com|
|July 25, 2014, Fri..||In-person workshop: Measuring Rehabilitation Outcomes in Older Adults, Chicago, www.rehabmeasures.org|
|July 28 - Nov. 22, 2014, Mon.-Sat..||On-line course: Introduction to Rasch Measurement Theory (D. Andrich, I. Marais) www.education.uwa.edu.au/ppl/courses|
|Aug. 2-6, 2014, Sat.-Wed.||PROMS2014, Guangzhou, China: Sat.-Sun. workshops; Mon.-Wed. symposium, www.confchina.com|
|Aug. 8 - Sept. 5, 2014, Fri.-Fri.||On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com|
|Sept. 3-5, 2014, Wed.-Fri.||IMEKO International Measurement Confederation Symposium, Madeira Island, Portugal, www.imekotc7-2014.pt|
|Sept. 10-12, 2014, Wed.-Fri.||In-person workshop: Introductory Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric|
|Sept. 12 - Oct. 10, 2014, Fri.-Fri.||On-line workshop: Rasch Applications, Part I: How to Construct a Rasch Scale (W.P. Fisher), www.statistics.com|
|Sept. 15-17, 2014, Mon.-Wed.||In-person workshop: Intermediate Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric|
|Sept. 18-19, 2014, Thurs.-Fri.||In-person workshop: Advanced Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric|
|Oct. 8-10, 2014, Wed.-Fri.||IACAT Conference: International Association of Computerized Adaptive Testing, Princeton, NJ, iacat.org/conference|
|Oct. 17 - Nov. 14, 2014, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com|
|Dec. 3-5, 2014, Wed.-Fri.||In-person workshop: Introductory Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric|
|Jan. 12-14, 2015, Mon.-Wed.||6th Rasch Conference: Sixth International Conference on Probabilistic Models for Measurement in Education, Psychology, Social Science and Health, Cape Town, South Africa www.rasch.co.za/conference.php|
|April 16-20, 2015, Thurs.-Mon.||AERA Annual Meeting, Chicago IL www.aera.net|