No possibility of a selection bias, but direct evidence of a simultaneous superiority effect: a reply to Wells et al.
The AJS field study was conducted across four different sites (Austin, Texas; Tucson, Arizona; Charlotte-Mecklenburg, North Carolina; and San Diego, California), but nearly 70 % of the lineups were administered at the Austin, Texas site alone. To retain most of the data while eliminating site variance (in an effort to maximize power), our evidentiary strength ratings study was limited to the lineups administered in Austin. We found that suspects identified from those simultaneous and sequential lineups were more likely to be associated with independent evidence of guilt if they had been identified from a simultaneous lineup than from a sequential lineup. In other words, we observed a significant simultaneous superiority effect. Wells et al. (this issue) point out that the simultaneous suspects were also more likely to be adjudicated guilty (77.3 % of simultaneous suspects were adjudicated guilty against 53.3 % of sequential suspects), which they regard as evidence of a sampling bias. However, all suspect ID cases from Austin that could possibly be included in our ratings study were included (i.e., we did not randomly sample a subset of suspect ID cases). Thus, what appears to be a selection bias to Wells et al. is actually further direct evidence of a simultaneous superiority effect.
KeywordsEyewitness identification ROC analysis Sequential lineups Simultaneous lineups
- Amendola, K. L., & Wixted, J. T. (2015). Comparing the diagnostic accuracy of suspect identifications made by actual eyewitnesses from simultaneous and sequential lineups in a randomized field trial. Journal of Experimental Criminology.Google Scholar
- Amendola, K. L., Valdovinos, M. D., Hamilton, E. E., Slipka, M. G., Sigler, M., & Kaufman, A. (2014). Photo arrays in eyewitness identification procedures: Presentation methods, influence of ID decisions on experts' evaluations of evidentiary strength, and follow-up on the AJS Eyewitness ID Field Study. Washington, DC: Police Foundation http://www.policefoundation.org/sites/glfiles/g798246/f/201403/FINAL%20EWID%20RBPORT-Police%20Foundation%281%29-1_O.pdf.
- Mickes, L., Flowe, H. D., & Wixted, J. T. (2012). Receiver operating characteristic analysis of eyewitness memory: Comparing the diagnostic accuracy of simultaneous and sequential lineups. Journal of Experimental Psychology: Applied, 18, 361–376.Google Scholar
- National Research Council. (2014). Identifying the Culprit: Assessing Eyewitness Identification. Washington, DC: The National Academies Press.Google Scholar
- Wells, G. L., Steblay, N. K., & Dysart, J. E. (2011). A test of the simultaneous vs. sequential lineup methods: An initial report of the AJS national eyewitness identification field studies. Des Moines, Iowa: American Judicature Society. Retrieved from: http://www.popcenter.org/library/reading/PDFs/lineupmethods.pdf.
- Wells, G. L., Steblay, N. K., & Dysart, J. E. (2014). Double-blind photo-lineups using actual eyewitnesses: An experimental test of a sequential versus simultaneous lineup procedure. Law and Human Behavior.Google Scholar
- Wells, G. L., Steblay, N. K., & Dysart, J. E. (2015). The flaw in Amendola and Wixted’s conclusion on simultaneous versus sequential lineups. Journal of Experimental Criminology. doi: 10.1007/s11292-014-9225-4.
- Wixted, J. T. & Mickes, L. (2012). The field of eyewitness memory should abandon “probative value” and embrace Receiver Operating Characteristic analysis. Perspectives on Psychological Science, 7, 275–278.Google Scholar