Trizano-Hermosilla Italo, Alvarado Jesús M
Department of Psychology, University of La FronteraTemuco, Chile; Department of Social Psychology and Methodology, University Autonoma de MadridMadrid, Spain.
Department of Methodology of the Behavioral Sciences, University Complutense de Madrid Madrid, Spain.
Front Psychol. 2016 May 26;7:769. doi: 10.3389/fpsyg.2016.00769. eCollection 2016.
The Cronbach's alpha is the most widely used method for estimating internal consistency reliability. This procedure has proved very resistant to the passage of time, even if its limitations are well documented and although there are better options as omega coefficient or the different versions of glb, with obvious advantages especially for applied research in which the ítems differ in quality or have skewed distributions. In this paper, using Monte Carlo simulation, the performance of these reliability coefficients under a one-dimensional model is evaluated in terms of skewness and no tau-equivalence. The results show that omega coefficient is always better choice than alpha and in the presence of skew items is preferable to use omega and glb coefficients even in small samples.
克朗巴哈系数（Cronbach's alpha）是评估内部一致性信度最广泛使用的方法。即便其局限性已有充分记录，且存在诸如欧米伽系数（omega coefficient）或不同版本的全局系数（glb）等更好的选择，尤其是在应用研究中，各项目质量不同或分布呈偏态时具有明显优势，但该方法已证明对时间推移具有很强的抗性。本文通过蒙特卡洛模拟，在一维模型下，从偏态和非tau等价性方面评估了这些信度系数的性能。结果表明，欧米伽系数始终是比阿尔法系数更好的选择，并且在存在偏态项目的情况下，即使样本量较小，使用欧米伽系数和全局系数也更为可取。
