A counterintuitive hypothesis about employment interview validity and some supporting evidence

This study found mixed support for the hypothesis that the difference in criterion-related validity between unstructured and structured employment interviews is due solely to the greater reliability of structured interviews. Using data from prior meta-analyses, this hypothesis was tested in 4 data sets by using standard psychometric procedures to remove the effects of measurement error in interview scores from correlations with rated job performance and training performance. In the 1st data set, support was found for this hypothesis. However, in a 2nd data set structured interviews had higher true score correlations with performance ratings, and in 2 other data sets unstructured interviews had higher true score correlations. We also found that averaging across 3 to 4 independent unstructured interviews provides the same level of validity for predicting job performance as a structured interview administered by a single interviewer. Practical and theoretical implications are discussed.