Date of Award
Master of Science (MS)
After witnessing a crime, eyewitnesses are typically presented with a six-person lineup, either simultaneous or sequential, and asked to pick out the perpetrator from the six faces presented. These eyewitnesses may or may not be asked to provide a confidence rating for their decision. Current research remains split on if simultaneous or sequential lineups provide the best opportunity for correct identifications of the perpetrator (hits) while limiting incorrect identifications of innocent lineup members (false alarms or foil IDs), though most recently there has been a shift towards adopting the sequential procedure in police departments. Furthermore, it is not clear how accuracy shifts in the absence of a sequential stopping rule and if the act of giving confidence ratings impact lineup response outcomes and therefore should or should not be mandated for police eyewitness tasks. The experiment used a 2x2x2 design testing lineup type, sequential stopping rule procedure, and giving confidence ratings. Signal Detection Theory modeling is used to determine which popular measurement models best fit the observed data and the implications for their theoretical underpinnings. Results from the current study do not indicate a sequential advantage for discriminability over simultaneous lineups, nor a significant difference when using a stopping rule or not. Concurrent with expectations, the results indicate that giving confidence ratings do not impact the proportion of hits or false alarms across lineup types and procedures. Additionally, results lend support towards the application of Diagnostic Feature Detection Theory (Wixted & Micked, 2014) towards both simultaneous and sequential lineups.
Larson, Gabriella, "Comparing Response Outcomes for Simultaneous and Sequential Lineup Procedures" (2023). Theses - ALL. 723.