Effective size and defendant bias in eyewitness identification lineups

Two aspects of fairness in eyewitness identification lineups are discussed: the effective size of a lineup, and the degree of bias towards or away from the defendant. Procedures are proposed for measuring both aspects of lineup fairness and a range of hypothetical examples is given. An appendix discusses and explains procedural and computational details, and provides a table of critical ranges of identification proportions for lineups of varying sizes and for different numbers of observers.