Coefficient Alpha Interpret With Caution
Coefficient Alpha Interpret With Caution
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DOI：
10.5964/ejop.v9i4.653
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发表时间：
2013-11-01
影响因子：
3
通讯作者：
Panayides, Panayiotis
中科院分区：
文献类型：
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作者：
Panayides, Panayiotis
在许多验证研究中，严重依赖Cronbach α已经成为标准做法。然而，关于alpha的解释似乎有两个误解。首先，α被错误地认为是一维的指示，其次，α的值越高越好。本研究的目的是澄清这些误解与教育环境中使用的真实的数据。结果表明，高α值可以在多维尺度或测试给定足够数量的项目。因此，alpha不能表示一维性。同时，在某个点之后，较高的alpha值并不一定意味着较高的可靠性和更好的质量量表或测试。事实上，非常高的alpha值可能表明所考虑的结构的尺度长、平行项目或覆盖面窄。建议研究人员在报告α时要谨慎。
Heavy reliance on Cronbach's alpha has been standard practice in many validation studies. However, there seem to be two misconceptions about the interpretation of alpha. First, alpha is mistakenly considered as an indication of unidimensionality and second, that the higher the value of alpha the better. The aim of this study is to clarify these misconceptions with the use of real data from the educational setting. Results showed that high alpha values can be obtained in multidimensional scales or tests given a sufficient number of items. Therefore, alpha cannot be an indication of unidimensionality. At the same time, after a certain point, higher values of alpha do not necessarily mean higher reliability and better quality scales or tests. In fact very high values of alpha could be an indication of lengthy scales, parallel items or a narrow coverage of the construct under consideration. Researchers are advised to apply caution when reporting alpha.