Fair Lineups Improve Outside Observers' Discriminability, Not Eyewitnesses' Discriminability: Evidence for Differential Filler-Siphoning Using Empirical Data and the WITNESS Model
Fair lineups (good fillers) better sort between innocent and guilty suspect identifications than do biased lineups (poor fillers). Why are fair lineups better? Some argue that the fair-lineup advantage is an improvement in eyewitness discriminability through some mechanism such as diagnostic-feature detection. Others argue that the fair lineups do not improve eyewitnesses’ discriminability at all but instead improve the discriminability of outside observers who are privy to which lineups members are known-fillers (the differential filler-siphoning mechanism). Experiment 1 used a forced-choice paradigm to show that fair lineups do not improve eyewitness discriminability. The second experiment used the WITNESS model to show that differential filler-siphoning and the fair-lineup advantage readily surfaces and nicely patterns experimental data based on minimal assumptions even though witness memory strength was held constant. Together, these two experiments support differential filler-siphoning and the idea that fair lineups enhance the outside observer’s discriminability, not the eyewitness’s discriminability.This Unpublished paper published as Smith, Andrew & Smalarz, Laura & Wells, Gary & Lampinen, James & Mackovichova, Simona. (2020). Fair Lineups Improve Outside Observers' Discriminability, Not Eyewitnesses' Discriminability: Evidence for Differential Filler-Siphoning Using Empirical Data and the WITNESS Model. 10.13140/RG.2.2.23329.22887/1
