The Implicit Relational Assessment Procedure: Emerging reliability and validity data

• The IRAP seems to demonstrate shared and unique variability expected of implicit measures.
• Important questions of pragmatic validity require further investigation.
• Meta-analysis showed that reliability was comparable with other implicit measures.
• However, evidence for validity is partially obscured by questions around reliability.
• Demonstration of IRAP effects may elucidate understanding of implicit responses.

The Implicit Relational Assessment Procedure (IRAP) is a measure of ‘implicit cognition’ developed on the basis of a contemporary behavioural analysis of language and cognition. The IRAP has now been applied to a range of foci over 5 years of published research. A frequently-cited caveat in publications to date is the need for further research to gauge the reliability and validity of the IRAP as an implicit measure. This review paper will provide a critical synthesis of available evidence for reliability and validity. The review applies a multifaceted test-theory approach to validity, and reliability is assessed through meta-analysis of published data. The discussion critically considers reviewed IRAP evidence with reference to the extant literature on alternative implicit measures, limitations of studies to date, and broader conceptual issues.