An investigation of description quality from real-life interviews

The quantity and quality of descriptive information about perpetrators make s an important impact on criminal investigations. For over a decade, the Co gnitive Interview (CT) technique has received increasing research attention as a method to improve the accuracy and completeness of eyewitness recall, and such research has led to its incorporation into police training progra mmes. Although the CI has heen reported to improve both the quantity and qu ality of resultant information, none of the previous studies has measured i nformation quality from a police perspective. The study reported here is an extension of that of George (1991) and investigates the perceived quality of the descriptions of perpetrators from George's study. The quality of suc h descriptions, as judged by police officers, is compared across four inter view groups before and after training. These interview groups are: untraine d (control), CT, Conversation Management (CM) and CIS CM. Three measures of quality are investigated, two rating measures and one ranking measure. Unl ike the results of George's (1991) quantitative study, the results of this study do not strongly favour the CI. However, results are complicated by th e nature of the field study which included certain uncontrollable variables . In particular, differences in the number of perpetrators described had an impact on this study's results. The reasons for the differences between th is study's findings and those of quantitative studies are addressed, as wel l as important issues concerned with field experimentation which are highli ghted by the present results.