Ratings-based identification procedures

As discussed elsewhere in this volume, and at length in the broader literature, eyewitness identification evidence is common, compelling, and prone to error. Traditional identifications procedures - where witnesses either pick a lineup member or reject the lineup - suffer a number of limitations that contribute to these errors. First given the nature of the lineup environment, procedures that require categorical identification responses amplify the potential for non-memorial influences acting on witnesses' decision criteria to contribute to identification error. Social, environmental, and metacognitive influences can increase (or decrease) the likelihood a witness will pick someone, independent of the quality of the witness's memory for the culprit of the degree of match between individual lineup members and the witness's memory for the culprit (see Wells, 1993). Second despite being an intuitively obvious method of testing a witness's memory (or an investigator's hypothesis about the guilt of a suspect), a categorical identification response is often less informative that it might appear (Sauer & Brewer, 2015)