Rasch is a model of probability
that estimates person ability,
that estimates item difficulty,
that predicts response probability
nothing but a function of ability and difficulty.
Rasch is a model of uniformity
that places the values of person ability
and the values of item difficulty
on the same scale with no diversity.
Rasch is a model of sufficiency
that uses number right for estimating person ability
and count of correct responses for item difficulty;
that relates raw score to person ability
and response distribution to item difficulty
-- with no ambiguity.
Rasch is a model with invariance property
that fosters person-free estimation of item difficulty
and test-free estimation of person ability;
that frees difficulty estimates from sample peculiarity
and ability estimates from difference in test difficulty.
Rasch is a model with diagnosticity
that flags items away from unidimensionality,
or items with local dependency;
that identifies persons with response inconsistency,
or persons or groups measured with inappropriacy;
that maintains construct fidelity and enhances test validity.
Rasch is a model of ubiquity;
from educational assessment to sociology,
from medical research to psychology,
from item analysis to item banking technology,
from test construction to test equity ....
-- nothing beats its utility and popularity.
Huixing Tang
Tang H. (1996) What is Rasch? Rasch Measurement Transactions 10:2 p. 507.
What is Rasch? Tang H. Rasch Measurement Transactions, 1996, 10:2 p. 507
Forum | Rasch Measurement Forum to discuss any Rasch-related topic |
Go to Top of Page
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 | |
---|---|
Oct. 4 - Nov. 8, 2024, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
Jan. 17 - Feb. 21, 2025, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
May 16 - June 20, 2025, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
June 20 - July 18, 2025, Fri.-Fri. | On-line workshop: Rasch Measurement - Further Topics (E. Smith, Facets), www.statistics.com |
Oct. 3 - Nov. 7, 2025, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
The URL of this page is www.rasch.org/rmt/rmt102m.htm
Website: www.rasch.org/rmt/contents.htm