Omega over alpha for reliability estimation of unidimensional communication measures

Cronbach’s alpha (coefficient <i>α</i>) is the conventional statistic communication scholars use to estimate the reliability of multi-item measurement instruments. For many, if not most communication measures, <i>α</i> should not be calculated for reliability estimation. Instead, coefficient omega (<i>ω</i>) should be reported as it aligns with the definition of reliability itself. In this primer, we review <i>α</i> and <i>ω</i>, and explain why <i>ω</i> should be the new ‘gold standard’ in reliability estimation. Using Mplus, we demonstrate how <i>ω</i> is calculated on an available data set and show how preliminary scales can be revised with ‘<i>ω</i> if item deleted.’ We also list several easy-to-use resources to calculate <i>ω</i> in other software programs. Communication researchers should routinely report <i>ω</i> instead of <i>α</i>.