השוואת שיטות

	תוקף מבנה פוליטומי	מודל תגובה מדורג (GRM)
תחום	פסיכומטריה	פסיכומטריה
משפחה	Latent structure	Latent structure
שנת המקור	1992–2000	1969
הוגה השיטה	Building on Messick (1989) and IRT extensions by Masters, Muraki, and Samejima	Fumiko Samejima
סוג	Psychometric validity framework	Item response theory / polytomous IRT model
מקור מכונן	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.
כינויים	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
קשורות	6	7
תקציר	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.