Interviewing techniques and the assessment of statement credibility

The objective of this study is the development of an applicable comprehensive questioning and statement analysis procedure. One hundred and thirty-six male residents of the Wynne Unit of the Texas Department of Criminal Justice - Institutional Division (TDCJ - ID) witnessed a staged theft, and provided testimony. Interview formats followed semi-standardized scripts derived from Structured Interview, Inferential Interview and Cognitive Interview techniques. Participants were randomly assigned to one of six experimental conditions in a 2(honesty of reporting) x 3(interview technique) matrix. Results found a 62% classification accuracy for the Structured Interview, 68% for the Cognitive Interview and 82% for the Inferential Interview, when comparisons were made between treatment phases of each interview condition. When responses given to each interview segment were analysed, 83% of the Structured Interview transcripts were correctly identified, as were 91% of the Inferential and 92.9% of the Cognitive Interview statements. The desire to prevaricate while escaping detection produced statements which were systematically different from honest reporting, as seen in the variables of coherence, response length, type-token ratio, and verbal hedges. These results indicate a potential forensic utility for strategies which attempt to detect deception through a combination of qualitative and quantitative statement characteristics, and underscore the need for systematic, question-by-question analysis of eyewitness statements. Copyright (C) 2002 John Wiley Sons, Ltd.