The Field of Eyewitness Memory Should Abandon Probative Value and Embrace Receiver Operating Characteristic Analysis

Clark (2012) highlights an important issue that has received inadequate attention in the eyewitness memory literature: lineup procedures that reduce the false identification rate (a desirable effect) often tend to reduce the correct identification rate as well (an undesirable effect). Determining which procedure is diagnostically superior under those conditions is not easy. Clark (2012) showed that the procedure with the lower false identification rate could be associated with higher overall costs to society once costs and benefits are both taken into consideration. Beyond the issue of cost, we argue that Clark's (2012) observation has far reaching implications for evaluating the diagnostic performance of a lineup procedure. Specifically, the field of eyewitness memory has attempted to differentiate between lineup procedures by using various measures of probative value (such as the diagnosticity ratio). However, contrary to intuition, probative value is not a relevant consideration. Instead, lineup procedures should be compared using receiver operating characteristic analysis, as is routinely done in other applied fields (such as radiology).