The Implicit Relational Assessment Procedure demonstrates poor internal consistency and test-retest reliability: A meta-analysis

Evidence for the IRAP’s reliability and validity is mixed, with one meta-analysis concluding it has good criterion validity and potential for clinical assessment, and two others concluding that it demonstrates low reliability. Here, we extend this evidence based through meta-analyses of all published and unpublished studies conducted in two labs. Individual participant data was used to estimate both internal consistency and test-retest reliability across a large number of domains (k = 16) and participants (N = 1576). Results suggest that internal consistency is poor (α = .51, 95% CI [.46, .56]) and test-retest reliability is very poor (ICC = .20, 95% CI [.05, .34]). We conclude that researchers should be very cautious about choosing to employ the IRAP or when interpreting its results.