Cronbach’s Alpha is not a Measure of Unidimensionality or Homogeneity

Year 2014, Volume: 2 Issue: 3, 19 - 27, 01.09.2014

Vahit Bademci

Abstract

Reliability is a characteristic of scores, not tests or measurement instruments. One of the methods to estimate the reliability of the scores on a test or measurement instrument is Cronbach’s coefficient alpha method. In other words, Cronbach’s alpha is an estimate of the score reliability based on the internal consistency among the [item] scores. In addition to this, Cronbach’s coefficient alpha should not be interpreted as a measure of the test’s or the measurement instrument’s unidimensionality or taken as an index of the homogeneity of a measurement instrument. Briefly, Cronbach’s alpha is not a measure of unidimensionality or homogeneity.

Keywords

Cronbach’s alpha, score reliability, misconception, unidimensionality, factor analysis

Cronbach’ın Alfası, Tek Boyutluluğun veya Benzeşikliğin (Homojenliğin) Bir Ölçüsü Değildir

Abstract

Güvenirlik, testler veya ölçme araçlarının değil, ölçümlerin bir özelliğidir. Cronbach’ın alfası katsayısı yöntemi, bir test ya da ölçme aracından elde edilen ölçümlerin güvenirliğini kestirme yöntemlerinden biridir. Başka bir ifadeyle, Cronbach’ın alfası, [madde] ölçümler[i] arasındaki iç tutarlılık üzerine temellenmiş bir ölçüm güvenirliğinin kestirilmesidir. Bunun yanı sıra, Cronbach’ın alfası katsayısı, ölçme aracının benzeşikliğinin (homojenliğinin) bir göstergesi olarak alınmamalı veya testin ya da ölçme aracının tek boyutluluğunun (bir boyutluluğunun) bir ölçüsü olarak yorumlanmamalıdır. Kısaca, Cronbach’ın alfası, benzeşikliğin veya tek boyutluluğun bir ölçüsü değildir.

Keywords

Anahtar Kelimeler:Cronbach’ın alfası, ölçüm güvenirliği, yanıltmaç (kavram yanılgısı), tek boyutluluk (bir boyutluluk), faktör analizi (etken çözümlemesi)

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