The role of encoding and systems variables in face identification

Michele L Cox, Purdue University

Abstract

There has been a movement among eyewitness researchers to ignore estimator variables (e.g., encoding conditions) and instead, concentrate on systems variables (e.g., lineup types). The possibility exists, however, that those exposed to poor encoding conditions may not benefit from certain eyewitness procedures designed to enhance performance. One purpose of the present research was therefore to investigate whether or not those exposed to poor v. good encoding conditions perform similarly given certain lineup procedures. In addition, a memory instruction was manipulated in an effort to elicit "reject lineup" responses from those exposed to poor encoding conditions. Finally, the elusive accuracy-confidence relationship was also investigated. Subjects initially viewed a good or poor picture of a target male. After a 30-minute filler task, subjects were either given a memory instruction (i.e., think about the adequacy of your memory in recognizing the target) or not, and subsequently completed pre-lineup confidence measures. Subjects then attempted to identify the target in a lineup that either contained the target or did not, was presented sequentially or simultaneously, and where the lineup members all resembled the target or were dissimilar. After the identification task, subjects completed post-lineup confidence measures. The results indicated that in target-absent conditions, sequential lineups improved performance over simultaneous lineups, but only when lineup members were dissimilar. Surprisingly, the memory instruction proved detrimental to those exposed to poor encoding conditions, however, the instruction did significantly benefit the performance of good encoders. The memory instruction also decreased the confidence of poor encoders in general, and was found to moderate the confidence-accuracy relationship. The results are discussed in terms of Jacoby's (1988) memory conceptualization.

Degree

Ph.D.

Advisors

Smith, Purdue University.

Subject Area

Social psychology

COinS