手法を比較

	ポリトマス・ラッシュモデル	ラッシュモデル
分野	心理測定学	心理測定学
系統	Latent structure	Latent structure
提唱年	1978–1982	1960
提唱者	Gerhard N. Masters (Partial Credit Model); David Andrich (Rating Scale Model)	Georg Rasch
種類	Item response model	Item Response Theory / Latent trait model
原典	Masters, G. N. (1982). A Rasch model for partial credit scoring. Psychometrika, 47(2), 149–174.	Rasch, G. (1960). Probabilistic Models for Some Intelligence and Attainment Tests. Danish Institute for Educational Research, Copenhagen.
別名	PRM, Rating Scale Model, Partial Credit Model, Polytomous IRT Rasch	1PL IRT, one-parameter logistic model, Rasch Modeli — 1PL IRT, 1PL model
関連	6	6
概要	The Polytomous Rasch Model extends the dichotomous Rasch framework to ordered response scales with three or more categories, such as Likert items or partial-credit tasks. It estimates person ability and item difficulty on the same interval-level logit scale, and it tests whether the response categories function as intended — prerequisites for rigorous ordinal measurement.	The Rasch model, introduced by Georg Rasch in 1960, is the simplest member of the Item Response Theory (IRT) family. It assigns a single difficulty parameter to each test item and places both item difficulties and person abilities on the same logit scale, enabling direct, sample-independent comparison of items and persons.