Compara mètodes

	Model de Rasch	Model de Resposta Graduada (GRM)
Camp	Psicometria	Psicometria
Família	Latent structure	Latent structure
Any d'origen	1960	1969
Autor original	Georg Rasch	Fumiko Samejima
Tipus	Item Response Theory / Latent trait model	Item response theory / polytomous IRT model
Font seminal	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.
Àlies	1PL IRT, one-parameter logistic model, Rasch Modeli — 1PL IRT, 1PL model	Samejima's GRM, Derecelendirilmiş Tepki Modeli (GRM), graded IRT model
Relacionats	6	7
Resum	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.