Data sets in the social and behavioral sciences are often heavy-tailed. Previous studies have demonstrated that small samples or leptokurtic distributions adversely affect the performance of coefficient alpha. To address these concerns, we propose an alternative estimator of reliability based on L-comoments. The empirical results of this study demonstrate that when sample sizes are small and distributions are heavy-tailed that the proposed coefficient L-alpha has substantial advantages over Cronbach’s estimator of reliability in terms of relative bias and relative standard error.
Headrick, Todd C. and Sheng, Yanyan. "A Proposed Measure Of Internal Consistency Reliablilty: Coefficient L-alpha." (Jan 2013).