手法を比較

	ショートフォーム・ラッシュモデル	項目応答理論 (IRT)
分野	心理測定学	心理測定学
系統	Latent structure	Latent structure
提唱年	1960 (Rasch model); short-form application from 1980s onward	1952–1968
提唱者	Georg Rasch	Frederic M. Lord (and Allan Birnbaum for the 2PL/3PL models)
種類	Probabilistic item response model	Probabilistic measurement model
原典	Rasch, G. (1960). Probabilistic models for some intelligence and attainment tests. Danmarks Paedagogiske Institut.	Lord, F. M. & Novick, M. R. (1968). Statistical Theories of Mental Test Scores. Addison-Wesley.
別名	Rasch analysis for abbreviated scales, short scale Rasch calibration, brief instrument Rasch model	IRT, latent trait theory, item characteristic curve theory, modern test theory
関連	6	5
概要	The short form Rasch model applies Rasch measurement theory to abbreviated instrument versions. Rather than using all items from a full scale, researchers select a reduced item set and calibrate it under the Rasch model to verify that the shortened instrument preserves interval-level measurement, adequate person separation, and item fit, enabling efficient yet rigorous measurement with fewer items.	Item response theory models the probability that a respondent answers an item correctly (or endorses it) as a function of the respondent's latent trait level and the item's own statistical properties — difficulty, discrimination, and guessing. Unlike classical test theory, IRT places persons and items on the same scale, yielding measurement that is sample-independent for items and test-independent for persons.