Item Response Theory (IRT) is a psychometric approach that focuses both on the subjects’ response to a test item as well as the qualities of the test items. In particular, we focus on the Rasch model for IRT.
Topics
- Motivation for Rasch Analysis
- Basic Concepts of Rasch Analysis
- Building a Rasch Model (UCON version)
- Wright Map
- Guessing
- Real Statistics Support for a dichotomous UCON model
- PROX model
- Building a PROX model
- Real Statistics Support for a PROX model
- Expanded view of ability and difficulty
- Polytomous Model Basic Concepts
- Building a Polytomous UCON model
- Polytomous Model Fit
- Real Statistics Support for a Polytomous UCON model
References
Moultan, M. H. (2003) Rasch estimation demonstration spreadsheet
https://www.rasch.org/moulton.htm
Wright, B. D. and Stone, M. H. (1979) Best test design. MESA Press: Chicago, IL
https://research.acer.edu.au/measurement/1/
Wright, B. D. and Masters, J. N. (1982) Rating scale analysis. MESA Press: Chicago, IL
https://research.acer.edu.au/measurement/2/
Boone, W. J. (2016) Rasch analysis for instrument development: why, when, and how?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5132390/pdf/rm4.pdf
Boone, W. J. and Noltemeyer, A. (2017) Rasch analysis: A primer for school psychology researchers and practitioners. Cogent Education
https://edisciplinas.usp.br/mod/resource/view.php?id=3333001
Furr, M. and Bacharach, V. R. (2007) Psychometrics: an introduction; Chapter 13: Item response theory and Rasch models. Sage Publishing
https://in.sagepub.com/sites/default/files/upm-binaries/18480_Chapter_13.pdf
Wright, B. and Stone, M. (1999) Measurement essentials, 2nd ed.
https://www.rasch.org/measess/
I am conducting my dissertation about item response theory. I would like to know how the scores in the teat is computed using the irt models. For instance 2 students got 26 out of 40 questions but they differ in the items they correctly answered the test. Can you help me or show me how scores in the teat is computed…
Jerome,
In the version of IRT that I describe all questions count equally. A correct answer counts 1 and an incorrect answer counts 0. If you correctly answer 26 out of 40 questions then your score is 26/40 = 65%.
Rasch Item Response Theory takes a different approach. See
https://real-statistics.com/reliability/item-response-theory/
Charles