手法を比較

	順序項目分析	順序型クロンバックのα係数
分野	心理測定学	心理測定学
系統	Latent structure	Latent structure
提唱年	1950s–1980s	2007
提唱者	Classical test theory tradition (Guilford, Nunnally, and others)	Zumbo, Gadermann, and Zeisser
種類	Item-level diagnostic	Internal consistency reliability coefficient
原典	Nunnally, J. C. & Bernstein, I. H. (1994). Psychometric Theory (3rd ed.). McGraw-Hill. ISBN: 978-0070474659	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.
別名	item analysis for ordinal data, polytomous item analysis, Likert item analysis, OIA	alpha for ordinal data, polychoric alpha, ordinal reliability coefficient, alpha based on polychoric correlations
関連	6	3
概要	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.	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.