Methoden vergleichen

	Polytome Konstruktvalidität	Polytomes Rasch-Modell
Fachgebiet	Psychometrie	Psychometrie
Familie	Latent structure	Latent structure
Entstehungsjahr	1992–2000	1978–1982
Urheber	Building on Messick (1989) and IRT extensions by Masters, Muraki, and Samejima	Gerhard N. Masters (Partial Credit Model); David Andrich (Rating Scale Model)
Typ	Psychometric validity framework	Item response model
Wegweisende Quelle	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.
Aliasnamen	polytomous item construct validity, ordered-category construct validity, polytomous measurement validity, multi-category scale validity	PRM, Rating Scale Model, Partial Credit Model, Polytomous IRT Rasch
Verwandt	6	6
Zusammenfassung	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 Polytomous Rasch Model extends the dichotomous Rasch framework to ordered response scales with three or more categories, such as Likert items or partial-credit tasks. It estimates person ability and item difficulty on the same interval-level logit scale, and it tests whether the response categories function as intended — prerequisites for rigorous ordinal measurement.