Methoden vergelijken

	Polytome valide construct	Graded Response Model (GRM)
Vakgebied	Psychometrie	Psychometrie
Familie	Latent structure	Latent structure
Jaar van ontstaan	1992–2000	1969
Grondlegger	Building on Messick (1989) and IRT extensions by Masters, Muraki, and Samejima	Fumiko Samejima
Type	Psychometric validity framework	Item response theory / polytomous IRT model
Oorspronkelijke bron	Muraki, E. (1992). A generalized partial credit model: Application of an EM algorithm. Applied Psychological Measurement, 16(2), 159–176.	Samejima, F. (1969). Estimation of Latent Ability Using a Response Pattern of Graded Scores. Psychometrika Monograph Supplement, No. 17.
Aliassen	polytomous item construct validity, ordered-category construct validity, polytomous measurement validity, multi-category scale validity	Samejima's GRM, Derecelendirilmiş Tepki Modeli (GRM), graded IRT model
Verwant	6	7
Samenvatting	Polytomous construct validity refers to the evaluation of whether a scale composed of ordered, multi-category items (e.g., Likert or rating-scale items) genuinely measures the intended latent construct. It extends classical validity frameworks to polytomous measurement models — such as the Graded Response Model or Generalized Partial Credit Model — ensuring that ordered response categories function as designed and that the resulting scores reflect the target construct.	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.