A Measure of Perceived Informativeness for Investigations of Eyewitness Memory Reporting

Despite the importance of eyewitness reports in police investigations, there are many unanswered questions about why witnesses report what they do. For example, they sometimes withhold accurate coarse-grain information, instead providing inaccurate fine-grain answers. Researchers argue that witnesses prefer fine-grain reports because they perceive them to be more informative, with informativeness operationalized as the specificity of the information provided. We examined how eyewitnesses (N = 150) perceive informativeness, developing extended and brief measures of perceived informativeness. The associated psychometric evaluation revealed that witnesses construe informativeness not only in terms of specificity but also in terms of their perceptions of the value of the information they report and its impact on the image they present. Using these measures to understand witnesses’ motivations for reporting or withholding information could advance understanding of the drivers of memory reporting in criminal investigations and various other domains involving investigative interviews.