Methoden vergleichen

	Ordnungsgemäße Cronbachs Alpha	Ordinal Item Analysis
Fachgebiet	Psychometrie	Psychometrie
Familie	Latent structure	Latent structure
Entstehungsjahr	2007	1950s–1980s
Urheber	Zumbo, Gadermann, and Zeisser	Classical test theory tradition (Guilford, Nunnally, and others)
Typ	Internal consistency reliability coefficient	Item-level diagnostic
Wegweisende Quelle	Zumbo, B. D., Gadermann, A. M., & Zeisser, C. (2007). Ordinal versions of coefficients alpha and theta for Likert rating scales. Journal of Modern Applied Statistical Methods, 6(1), 21–29.	Nunnally, J. C. & Bernstein, I. H. (1994). Psychometric Theory (3rd ed.). McGraw-Hill. ISBN: 978-0070474659
Aliasnamen	alpha for ordinal data, polychoric alpha, ordinal reliability coefficient, alpha based on polychoric correlations	item analysis for ordinal data, polytomous item analysis, Likert item analysis, OIA
Verwandt	3	6
Zusammenfassung	Ordinal Cronbach's alpha is a reliability coefficient computed from polychoric or polyserial correlations rather than Pearson correlations, making it appropriate for Likert-type and other ordinal item response data. It corrects the systematic downward bias that standard Cronbach's alpha produces when items are treated as continuous but are actually ordinal.	Ordinal item analysis evaluates each individual item in a rating-scale or Likert-type instrument using descriptive and correlational statistics suited to ordered categorical response formats. It guides item selection and refinement by flagging items with problematic difficulty, poor discrimination, or low corrected item-total correlations before reliability and validity studies proceed.