An Aberrant Abundance of Cronbach’s Alpha Values at .70

Cronbach’s α is the most widely reported metric of the reliability of psychological measures. Decisions about an observed α’s adequacy are often made using rule-of-thumb thresholds, such as α of at least .70. Such thresholds can put pressure on researchers to make their measures meet these criteria, similar to the pressure to meet the significance threshold with p values. We examined whether α values reported in the psychology literature are inflated at the rule-of-thumb thresholds (αs = .70, .80, .90) because of, for example, overfitting to in-sample data (α-hacking) or publication bias. We extracted reported α values from three very large data sets covering the general psychology literature (> 30,000 α…

• NS
  National Science Foundation

  Award: 1424231
• SF
  SHRM Foundation
• DF
  Deutsche Forschungsgemeinschaft

  Award: 464488178
• SS
  Social Sciences and Humanities Research Council

  Award: 869-2013-003