방법 비교

	Rasch 모형	GRM
분야	심리측정학	심리측정학
계열	Latent structure	Latent structure
기원 연도	1960	1969
창시자	Georg Rasch	Fumiko Samejima
유형	Item Response Theory / Latent trait model	Item response theory / polytomous IRT model
원전	Rasch, G. (1960). Probabilistic Models for Some Intelligence and Attainment Tests. Danish Institute for Educational Research, Copenhagen.	Samejima, F. (1969). Estimation of Latent Ability Using a Response Pattern of Graded Scores. Psychometrika Monograph Supplement, No. 17.
별칭	1PL IRT, one-parameter logistic model, Rasch Modeli — 1PL IRT, 1PL model	Samejima's GRM, Derecelendirilmiş Tepki Modeli (GRM), graded IRT model
관련	6	7
요약	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.	The Graded Response Model is an item response theory model developed by Fumiko Samejima in 1969 for ordered polytomous items such as Likert-type scales. It estimates both the discriminating power of each item and a set of threshold parameters marking the boundaries between adjacent response categories, while simultaneously placing persons on a continuous latent trait scale.