All the components of the lineup task are compared with parts of a social psychology experiment. The officer conducting the lineup is the experimenter, the eyewitnesses are the subjects, instructions to the witnesses constitute the experimental protocol, the suspect is the stimulus, and the selection of lineup members and the positioning of the suspect in the lineup constitutes the design. In addition, the eyewitness' selection in the lineup simulates the data which will be evaluated by the police, and, subsequently, by the prosecutor, judge, and jury. Similar to an experiment, demand characteristics, experimenter bias, and lack of control groups can influence the results. A staged-crime paradigm can be used to manipulate systematically the lineup design and procedures to study the impact of variations on rates of false and accurate identifications. Lineup research examples from experiment analysis, especially the mock witness control group and the blank lineup control group, are then described to illustrate improvements in the structure and procedure involved in police lineup using this analogy. 2 tables, 2 notes, and 35 references