Whereas most humans spend their time trying to get things right,
psycholo- gists are perversely dedicated to error. Errors are
extensively used to in- vestigate perception, memory, and performance;
some clinicians study errors like tea leaves for clues to unconscious
motives; and this volume presents the work of researchers who, in an
excess of perversity, actually cause people to make predictable errors
in speech and action. Some reasons for this oddity are clear. Errors
seem to stand at the nexus of many deep-psychological questions. The
very concept of error presupposes a goal or criterion by comparison to
which an error is an error; and goals bring in the foundation issues of
control, motivation, and volition (Baars, 1987, 1988; Wiener, 1961).
Errors serve to measure the quality of performance in learning, in
expert knowledge, and in brain damage and other dysfunctional states;
and by surprising us, they often call attention to phenomena we might
otherwise take for granted. Errors also seem to reveal the "natural
joints" in perception, language, memory, and problem solving-revealing
units that may otherwise be invisible (e. g., MacKay, 1981; Miller,
1956; Newell & Simon, 1972; Treisman & Gelade, 1980).