Methoden vergelijken

	Polytome valide construct	Partial Credit Model (PCM / GPCM)
Vakgebied	Psychometrie	Psychometrie
Familie	Latent structure	Latent structure
Jaar van ontstaan	1992–2000	1982
Grondlegger	Building on Messick (1989) and IRT extensions by Masters, Muraki, and Samejima	Geoff N. Masters (PCM, 1982); Eiji Muraki (GPCM, 1992)
Type	Psychometric validity framework	Item Response Theory / Polytomous IRT
Oorspronkelijke bron	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.
Aliassen	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
Verwant	6	5
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 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.