방법 비교

	GRM	3모수 로지스틱 문항반응이론 모형 (3PL)
분야	심리측정학	심리측정학
계열	Latent structure	Latent structure
기원 연도	1969	1968
창시자	Fumiko Samejima	Allan Birnbaum
유형	Item response theory / polytomous IRT model	Item response model / latent trait model
원전	Samejima, F. (1969). Estimation of Latent Ability Using a Response Pattern of Graded Scores. Psychometrika Monograph Supplement, No. 17.	Birnbaum, A. (1968). Some latent trait models and their use in inferring an examinee's ability. In F. M. Lord & M. R. Novick (Eds.), Statistical theories of mental test scores (pp. 397–479). Addison-Wesley.
별칭	Samejima's GRM, Derecelendirilmiş Tepki Modeli (GRM), graded IRT model	3PL IRT — Üç Parametreli Madde Tepki Modeli, three-parameter logistic model, 3PLM, Birnbaum model
관련	7	5
요약	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.	The three-parameter logistic (3PL) model, introduced by Allan Birnbaum in 1968, is an item response theory model that describes the probability of a correct response to a binary test item as a function of three item-level parameters — difficulty, discrimination, and a lower asymptote representing guessing — and one person-level parameter representing latent ability.