Fisher et al., (1986) – ‘Enhancement of eyewitness memory with the cognitive interview’, American Journal of Psychology
This study is also referred to as:
- Fisher et al., (1986)
- Fisher and Geiselman (1986)
- Geiselman et al., (1986)
Background
Fisher et al., (1986) focuses on police interviews of witnesses.
What is an interview?
An interview is simply trying to elicit information from a person or witness, while keeping the information valid. This is easier said than done. You may remember two studies from AS: Loftus et al., (1974) and Samuel and Bryant (1984), which demonstrate this. Firstly, Loftus showed the impact that leading questions could have upon participant recall and she concluded that an actual change in memory had occurred. Memory is easily malleable, changing how a question is asked can change the memory itself. Secondly, Samuel and Bryant showed the impact of repeating the same question. Repeating the same question to children will cause them to completely change their answer, even if their answers were perfectly correct.
One of the most important aspects of police work is the ability it obtain accurate and detailed information from eyewitnesses of crime. One experienced judge has stated that incorrect eyewitness identifications have led to more miscarriages of justice than all other factors combined (Sobel,1972).
This study focuses not at the normal interviews that the police conduct, but something called the enhanced cognitive interview.
“This research evaluated an innovative interview procedure, the cognitive interview, that was designed to aid eyewitnesses recall of the details of crimes.”
– (Fisher et al., 1986)
The enhanced cognitive interview has two underlining assumptions:
- It is possible to access memories from different retrieval points.
- Retrieval from memory will be more effective if at the time of retrieval the context of the original event can be reinstated.
There are four main retrieval mnemonics to the cognitive interview:
- Interview Similarity — An attempt to reinstate the context of memory, interviews must take account of the external factors. How were the participants feeling emotionally? What was the weather like? “Mentally reinstating the context that surrounded a to-be-remembered event has been shown to be a powerful memory aid in numerous laboratory experiments.” – (Fisher and Geiselman, 1989)
- Focused Retrieval — This is also called free recall. Interviewees are encouraged to recall as much as possible without interruptions from the person conducting the interview.
- Extensive Retrieval — The interviewer makes as many attempts as possible at retrieval from many entry points, for example: what happened when you entered the building? What happened when you left the building? Irrelevant parts are requested by the interviewer in order to maximise the amount recalled, as the more irrelevant details that the interviewee recalls the more likely they are to remember something significant through association, for example, you might have noticed the something peculiar about the carpet and that led you to recall the criminals shoes.
- Witness – Compatible Questioning — Each witness will be different, have different values and perceptions and thus the interviewer should consider that.
Aim
To identify and develop methods to enhance the completeness and accuracy of eyewitness reports and to test these methods empirically in controlled, yet ecologically valid, laboratory settings.
Simpler version: To study and test the cognitive interview in the field.
Design
Experiment One
Lab experiment. The 51 non-student volunteers watched police training films of simulated violent crimes.
48 Hours later, the participants of Fisher and Geiselman’s experiment one, were subjected to questioned in interactive interviews by experimented police officers.
Experiment Two
Lab experiment
Participants
Experiment One
51 non-student volunteers, which were recruited from advertisements placed in a local paper and in the University of California. The participants had a variety of occupations. All the participants were paid $20 for their participation in the study and they were informed about the study before they completed it.
16 Police detectives from the Robbery Division of Dade County, Florida. All the police detectives had served a minimum of five years in the division. Were used as the interviewers for the study, these were paid $50 for their participants.
Experiment Two
60 participants, who were students at the University of California studying an introduction to Psychology. The participants were participating for course credit.
Procedure
Experiment One
The 51 participants watched the video in groups of between 8-12, they were given instructions not to confer with each other about the film for the 48 hours between the interviews.
9 of the Police detectives conducted cognitive interviews after the 33 of the participants watched the videos. The other 7 conducted standard interviews on the other 18 of participants. The participants were randomly assigned to an interview condition.
Experiment Two
The 60 participants were shown a film of a staged bank robbery in groups of 8-10.
Around 5 minutes after watching the film the participants were given two sheets of lined paper and 20 minutes to recall details about the film.
14 subjects received control instructions:
“We would like you to write down as many of the facts as you can remember about the film you just saw. Please put each fact you can remember on a separate line. Do not worry about writing down somethings out of order. Write down the facts as they come to you, but write legibly.”
15 subjects received reinstate context instructions in addition to the control instructions:
“ Before you begin, reinstate in your mind the context surrounding the incident. Think about what the surrounding environment looked like at the scene,such as rooms,the weather, any nearby people or objects. Also, think about how you were feeling at the time and think about your reactions to the incident.”
16 subjects received the be-complete instructions in addition to the control instructions:
“ Some people hold back information because they are not quite sure that what they remember is important. Please do not edit anything out. Please write down everything,even things you think may not be important.It is necessary that you be complete.”
The remaining 15 subjects received instructions of the four cognitive interview mnemonics.
All conditions were scored by a laboratory assistant who was blind to the conditions.
Results
Experiment One
Results from experiment one, showed that more correct information was elicited when the cognitive interview was used, as opposed to the standard police interview. Furthermore, the information elicited from the cognitive interviews were also without an increase in confabulation and incorrect information.
Experiment Two
Significantly more correct information was provided by the participants who were instructed to use the four mnemonics.
Conclusions
“The purpose of this research was to develop and evaluate methods based on current memory theory to enhance the completeness and accuracy of eyewitness reports.”
– (Fisher et al., 1986)
The cognitive interviews elicited more information than the regular interviews. The Fisher and Geiselman conclude that these results or enhanced memory in the witnesses were not due to increased motivation in the interviewers or witnesses.
Both Fisher and Geiselman recommend that the cognitive interview be used in real police interviews, as they elicit more correct information, without taking significantly longer to conduct.
This study is also referred to as:
- Fisher et al., (1986)
- Fisher and Geiselman (1986)
- Geiselman et al., (1986)
Fisher et al., Evaluation
+ Laboratory experiments are high in controls and therefore highly valid.
+ Reliability. As the experiment was replicated with the similar results, we can say that the experiment is high in reliability. As the second experiment eliminated the interviewer as an extraneous variable we can say that it is highly likely that the cognitive interview mnemonics and structuring is causing the effect of increased recall.
+ High Standardisation, the experiment is highly standardised, each participant was subject to the same video.
– Demand characteristics, as the non-students were paid $20, the students given extra credit and the police detectives were paid $50 for participating, they may have feel the need to act in a way which the experimenter would want.
+ Ecological Validity, as experiment one used real police detectives, we can say that the experiment is high in ecological validity. However, we can also argue the opposite as the participants only saw a film of a crime and not a real crime.
+ Ethics, as the participants were informed about the interview beforehand, we can say that the study was ethical, however we can argue the opposite as the participants were paid for their participation, which is against the BPS’s code of ethics.
– Ethnocentrism, the study was only focused on students from the University of California.
+ Experimenter bias, as the results of both experiments were analysed by laboratory assistants who were blind to the conditions, we can say that the study is lacking in experimenter bias, which is a strength.
+ Construct Validity, the results of the study showed support for the effectiveness of the cognitive interview.
References
Further Reading
OCR A2 Psychology Student Unit Guide: Unit G543: Forensic Psychology (Student Unit Guides)
Thanks, I couldn’t find anything on Fisher and Geiselman (1989) anywhere.