Date of Award

Fall 1987

Project Type


Program or Major


Degree Name

Doctor of Philosophy


This investigation has sought to evaluate two disputed issues regarding experimental research on the influence of misleading postevent information on the remembering of originally experienced event information: (1) whether misinformation leads to memory impairment, and (2) whether experimental findings are generalizable to real world eyewitnesses.

Subjects were shown four critical event items in a series of slides. Afterward, all subjects were misinformed (misled condition) that for two of the event items, other items had appeared. No misinformation (control condition) was provided for the remaining two event items. Subjects made separate yes/no verbal recognitions on the original appearance of event items and novel items (items neither shown nor presented as misinformation). Assignments were counterbalanced.

The yes/no procedure tested the respective roles of two hypothesized processes. The coexistence hypothesis asserts that misleading postevent information leads to an impairment in the ability to access original event information. According to the no effect hypothesis, misleading postevent information only affects the responses of subjects who would ordinarily not remember the event information. Evidence for memory impairment arises if there are significantly more correct responses with the control versus misled conditions. If misinformation influences responses when the event information is not remembered, then, with event items tests, decreases in correct responses for the misled condition in comparison to the control condition will be matched by equivalent increases, with novel items tests, in correct responses for the misled versus control conditions.

Results are inconclusive with respect to memory impairment. Although responses were not significantly more often correct with control versus misled conditions, there was some indication that the misinformation led to a poorer ability to discriminate event from novel items. Results were conclusive that the misinformation influenced responses when the event information was not remembered. With event items tests, control performance reliably exceeded misled performance; with novel items tests, misled condition responses were significantly more often correct than control condition responses.

Results demonstrate that response accuracy depends on particular conditions. General statements regarding the response accuracy of real world eyewitnesses exposed to misinformation are unwarranted. Statements should be based on knowledge of specific circumstances.