title: The grain-size lineup: A test of a novel eyewitness identification procedure.
abstract: When making a memorial judgment, respondents can regulate their accuracy by adjusting the precision, or grain size, of their responses. In many circumstances, coarse-grained responses are less informative, but more likely to be accurate, than fine-grained responses. This study describes a novel eyewitness identification procedure, the grain-size lineup, in which participants eliminated any number of individuals from the lineup, creating a choice set of variable size. A decision was considered to be fine-grained if no more than 1 individual was left in the choice set or coarse-grained if more than 1 individual was left in the choice set. Participants (N = 384) watched 2 high-quality or low-quality videotaped mock crimes and then completed 4 standard simultaneous lineups or 4 grain-size lineups (2 target-present and 2 target-absent). There was some evidence of strategic regulation of grain size, as the most difficult lineup was associated with a greater proportion of coarse-grained responses than the other lineups. However, the grain-size lineup did not outperform the standard simultaneous lineup. Fine-grained suspect identifications were no more diagnostic than suspect identifications from standard lineups, whereas coarse-grained suspect identifications carried little probative value. Participants were generally reluctant to provide coarse-grained responses, which may have hampered the utility of the procedure. For a grain-size approach to be useful, participants may need to be trained or instructed to use the coarse-grained option effectively.
authors.affiliation: School of Psychology, Flinders University.
authors.forename: Ruth
authors.initials: R
authors.lastname: Horry
authors.affiliation: School of Psychology, Flinders University.
authors.forename: Neil
authors.initials: N
authors.lastname: Brewer
authors.affiliation: School of Psychology, Flinders University.
authors.forename: Nathan
authors.initials: N
authors.lastname: Weber
mesh_terms: D057237:Criminals; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall; D021641:Recognition, Psychology; D014743:Videotape Recording; D055815:Young Adult