Abstract
Cronbach's alpha is a commonly reported estimate to assess scale quality in health psychology and related disciplines. In this paper, we argue that alpha is an inadequate estimate for both validity and reliability - two key elements of scale quality. Omega is a readily available alternative that can be used for both interval and ordinal data. More importantly, we argue that factor-analytic evidence should be presented before assessing the internal structure of a scale. Finally, pointers for readers and reviewers of manuscripts on making judgements about scale quality are provided and illustrated by examples from the field of health psychology.
Original language | English |
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Pages (from-to) | 242-247 |
Number of pages | 6 |
Journal | Health Psychology Review |
Volume | 11 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2017 |
Keywords
- Scale quality
- alpha
- internal consistency
- validity
- reliability
- COEFFICIENT ALPHA
- RELIABILITY
- VALIDATION
- NUMBER
- ADOLESCENTS
- CONSTRUCTS
- VALIDITY
- ERROR