Comparison of Alpha, Stratified Alpha, and Omega Reliability Coefficients in Multidimensional Test Structures

Abstract

The aim of this research is to examine the reliability of multidimensional test structures. For this purpose, the estimations of the Cronbach Alpha, Stratified Alpha and Omega coefficients for a two-dimensional test were examined in the the data simulated under sample size (100,200 and 400), correlation between dimensions (0.00 and 0.50), correlation between items (0.30-0.50 and ≥0.65), test length (10 and 20) and the number of items per dimensions (5-5, 7-3, 10-10 and 15-1). As a result of the research, it was found that the Stratified Alpha and Omega values were higher than the general Alpha value.. In addition, it was concluded that the inter-item correlation condition was more effective than the interdimensional correlation on the estimations of the three reliability coefficients.

Keywords

• reliability
• Cronbach alpha
• stratified alpha
• omega

Çok Boyutlu Test Yapılarında Alfa, Tabakalı Alfa ve Omega Güvenirlik Katsayılarının Karşılaştırılması

Öz

Bu araştırmanın amacı, çok boyutlu test yapılarının güvenirliğinin incelenmesidir. Bu amaçla iki boyutlu bir test için örneklem büyüklüğü (100,200 ve 400), boyutlar arası korelasyon (0,00 ve 0,50), maddeler arası korelasyon (0,30-0,50 ve ≥0,65) , test uzunluğu (10 ve 20) ve boyutlara düşen madde sayısı (5-5, 7-3, 10-10 ve 15-1) koşulları altında üretilen verilerden Cronbach Alfa, Tabakalı Alfa ve Omega katsayılarının kestirim değerleri incelenmiştir. Araştırma sonucunda Tabakalı Alfa ve Omega değerlerinin genel Alfa değerinden yüksek fakat birbirine benzer sonuçlar verdiği bulunmuştur. Ayrıca üç güvenirlik katsayısının kestirimleri üzerinde maddeler arası korelasyon koşulunun boyutlar arası korelasyona göre daha etkili olduğu sonucuna ulaşılmıştır.

Anahtar Kelimeler

• güvenirlik
• Cronbach alfa
• tabakalı alfa
• omega

Kaynakça

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