Abstract
Although researchers have investigated factors that may influence the information that eyewitnesses provide, little attempt has been made to relate the information that an eyewitness provides to information that the police require. Therefore, researchers may be evaluating eyewitness performance simplistically. In this article, the argument that researchers investigating eyewitness performance should consider police requirements when evaluating the quality of information eyewitnesses provide is asserted. These requirements are (a) to discover whether a crime has been committed and if so, what crime; (b) to find evidence to identify the individual responsible; (c) to produce evidence that prevents a guilty criminal from using an inappropriate defense; and (d) to determine whether the eyewitness is telling the truth.