Methoden vergleichen

	Drei-Parameter-Logistisches IRT-Modell (3PL)	Zweiparametrisches logistisches IRT-Modell (2PL)
Fachgebiet	Psychometrie	Psychometrie
Familie	Latent structure	Latent structure
Entstehungsjahr	1968	1980
Urheber	Allan Birnbaum	Frederic M. Lord
Typ	Item response model / latent trait model	Item response model / latent trait model
Wegweisende Quelle	Birnbaum, A. (1968). Some latent trait models and their use in inferring an examinee's ability. In F. M. Lord & M. R. Novick (Eds.), Statistical theories of mental test scores (pp. 397–479). Addison-Wesley.	Lord, F. M. (1980). Applications of Item Response Theory to Practical Testing Problems. Erlbaum.
Aliasnamen	3PL IRT — Üç Parametreli Madde Tepki Modeli, three-parameter logistic model, 3PLM, Birnbaum model	two-parameter logistic model, 2PL model, 2PL IRT — İki Parametreli Madde Tepki Modeli
Verwandt	5	6
Zusammenfassung	The three-parameter logistic (3PL) model, introduced by Allan Birnbaum in 1968, is an item response theory model that describes the probability of a correct response to a binary test item as a function of three item-level parameters — difficulty, discrimination, and a lower asymptote representing guessing — and one person-level parameter representing latent ability.	The two-parameter logistic item response model, formalised by Frederic Lord (1980), describes the probability that a respondent answers a binary test item correctly as a smooth S-shaped function of the respondent's latent ability. By estimating a separate discrimination parameter for each item alongside a difficulty parameter, 2PL allows items to differ in how sharply they distinguish high- from low-ability respondents — making it the standard model for large-scale educational and psychological assessments.