PERCENTAGE AGREEMENT AND PHI: A CONVERSION TABLE

Abstract
Studies in applied behavior analysis have used two expressions of reliability for human observations: percentage agreement (including percentage occurrence and percentage nonoccurrence agreement) and correlational techniques (including the phi coefficient). The formal relationship between these two expressions is demonstrated, and a table for converting percentage agreement to phi, or vice‐versa, is presented. It is suggested that both expressions be reported in order to communicate reliability unambiguously and to facilitate comparison of the reliabilities from different studies.