Σύγκριση μεθόδων

	Πολυτομική Εγκυρότητα Δομής	Μοντέλο Μερικής Πίστωσης (PCM / GPCM)
Πεδίο	Ψυχομετρία	Ψυχομετρία
Οικογένεια	Latent structure	Latent structure
Έτος προέλευσης	1992–2000	1982
Δημιουργός	Building on Messick (1989) and IRT extensions by Masters, Muraki, and Samejima	Geoff N. Masters (PCM, 1982); Eiji Muraki (GPCM, 1992)
Τύπος	Psychometric validity framework	Item Response Theory / Polytomous IRT
Θεμελιώδης πηγή	Muraki, E. (1992). A generalized partial credit model: Application of an EM algorithm. Applied Psychological Measurement, 16(2), 159–176.	Masters, G. N. (1982). A Rasch model for partial credit scoring. Psychometrika, 47(2), 149–174.
Εναλλακτικές ονομασίες	polytomous item construct validity, ordered-category construct validity, polytomous measurement validity, multi-category scale validity	Kısmi Kredi Modeli (PCM / GPCM), Generalized Partial Credit Model, GPCM, PCM
Συναφείς	6	5
Σύνοψη	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 Partial Credit Model is an extension of the Rasch measurement framework designed for ordered polytomous items — items whose responses fall into more than two ordered categories, such as partial-credit tasks in performance assessment or open-ended scoring rubrics. Proposed by Geoff Masters in 1982 and later generalised by Eiji Muraki in 1992, the model estimates a separate threshold (step) parameter for each adjacent-category transition within every item, allowing fine-grained calibration of how much each additional credit level contributes to locating a person on the latent trait.