Not all effect sizes are the same: Comments on Holden (2008)

Despite the common belief that response bias is a significant moderator of psychological tests in field settings, these biases have been notoriously difficult to identify. Holden (2008) has recently presented evidence suggesting this paradox may at least in part be explained by problems inherent to the use of moderated regression with self-report indicators of response bias. His article offers an innovative proposal for understanding a central issue in applied test use. However, the conclusions drawn about both moderated regression and the general validity of response bias indicators are open to alternative explanations. It would be premature to assume these factors are important contributors to the ephemeral character of response bias effects.