The Cognitive Interview and Eyewitness Credibility My Initial Hypothesis Hypothesis: The cognitive interview increases the credibility of eyewitness testimony by decreasing memory error and confabulations. Information is the lifeblood of a criminal investigation. The ability of investigators to obtain useful and accurate information from eyewitnesses of crimes is crucial to effective law enforcement, yet full and accurate recall is difficult to achieve (Stewart, 1985).
Such elicitation of complete and accurate recall from people is important in many aspects of life; specifically, eyewitness recall may determine whether a case is solved. Principle advocates of the cognitive interview (Fisher, Geiselman, Holland & MacKinnon, 1986) claim that the said interviewing technique can increase both the quantity and quality of information obtained from an eyewitness.
Other empirical research surrounding the cognitive interview suggests the same idea: the cognitive interview increases the effectiveness of eyewitness memory retrieval during investigative interviews without any apparent negative consequences (Fisher, et al. , 1986). The Empirical Evidence By looking at studies related to the topic of cognitive interviewing as a means to elicit useful and accurate information from eyewitnesses, it becomes evident that not only is there a great interest in the subject, but that it is generally effective.
A study conducted by Fisher (1986) investigated whether the cognitive interview increases the credibility of eyewitness testimony. Sixteen detectives from the Robbery Division of Metro-Dade Police Department, Dade County, Florida were selected to perform a total of 88 interviews over a period of four months, and they were divided into two groups: one group was trained in the cognitive interview, and the other was untrained and served as the control. The interviews concerned primarily victims of commercial robbery and purse-snatching.
A significant difference was found between the experimental and control groups; specifically, the cognitive interview elicited 47 percent more information than the standard police investigation. However, 85 percent of all statements elicited under either condition were correct (Fisher, 1986). In summation, the study suggested that while the amount of information collected in the cognitive interview is greater, the cognitive interview does not necessarily improve the credibility of eyewitness accounts.
Another study conducted by Cutshall and Yuille (1989) also investigated whether the cognitive interview increases the credibility of eyewitness testimony. Several simulation experiments were undertaken, employing staged scenarios in Los Angeles Police Department training films that depicted realistic criminal events. The subjects were undergraduate students, and the interviewers were experienced law enforcement officials who were instructed to either implement standard police interviewing techniques, or cognitive interviewing techniques.
Subjects were interviewed by the interviewers approximately 48 hours after the viewing the film. The cognitive interview elicited 35 percent more correct information than did the standard interview, but the two types did not differ on incorrect information or confabulations (Cutshall & Yuille, 1989). Again, the study suggested that the amount of information collected in the cognitive interview is greater than standard police interviews, but the cognitive interview does not necessarily improve the credibility of eyewitness accounts.
Similar results have been found in a more recent, comparable field study conducted by Clifford and George (1992) with a group of British police investigators. Police investigators tape recorded interviews with real-life victims and witnesses of robbery prior to training, using standard police interviewing techniques. Half of the group underwent cognitive interview training over four 60-minute sessions, and later tape recorded real-life interviewing sessions using the newly learned technique.
Compared with the untrained group, the group trained in cognitive interviewing elicited a 47 percent increase in collected information than before training. Additionally, 94 percent of the statements from the interviews were corroborated with other witness testimony and forensic evidence, and there was no difference found in the corroboration rates of pre- and post-training interviews (Clifford and George, 1992). The cognitive interview did not increase the amount of incorrect information; conversely, neither did it decrease memory error and confabulations.
Thus far, research concerning the cognitive interview as it pertains to the effectiveness of eliciting increased amounts of information, as well as how it relates to the increased credibility of eyewitness testimony, has been evaluated. Some related research has looked at context of the recognition of suspects from photographs. Cutler, Martens and Penrod (1987) investigated context reinstatement, basing their procedure in part on the cognitive interview, as well as mnemonic instructions, a review of original descriptions, and the provision of snapshot details using slides.
A number of variables were manipulated in this study, including the presence or absence of disguise and biased instructions. The context interview had no significant effects on identification performance, but it did significantly reduce the effects of disguise, biased instructions and unfair lineups (Cutler et al. , 1987). This is important because if it can be shown that the cognitive interview can reduce false identifications and provide more complete and accurate reports, then the practical implications are valid.
However, the effectiveness of context reinstatement in cognitive interviewing must consider the extent to which mental reinstatement of context may be effective (Bull & Memon, 1991). A study conducted by Bekerian, Dennett, Hill and Hitchcock (1990) classified imaged details into two types: molar details which include the placement of people, environmental factors and physical appearances; and molecular details which include the specificity of the information being imagined.
The results indicated a significant increase in recall following imagery instructions, also reporting a proportional increase in errors. In summation, the picture that one obtains from an overview of the context is not reliable, and the combination of different context reinstatement procedures do not aid in the context of the recognition of suspects from photographs (Bekerian et al. , 1990). This method, too, does not necessarily improve the credibility of eyewitness accounts, nor does it even decrease memory error and confabulations.
My Current Opinion While the cognitive interview does prove to be effective in increasing the amount of accurate information elicited from witnesses of crimes, it does not necessarily increase the credibility of eyewitness testimony by reducing memory error and confabulations. The cognitive interview has been shown to elicit more information than the standard interview, but the two types do not differ on incorrect information or confabulations (Fisher, 1986; Cutshall and Yuille, 1989; Clifford and George, 1992).
The empirical evidence rejects the proposed hypothesis. Further research conducted by Thomson and Tulving (1973) suggests the several theoretical and practical issues are present when using the cognitive interviewing technique to increase witness recall and credibility; the most important being the distinction between recognition and recall processes. An eyewitness may be required to describe what the murder weapon looked like, or the suspected murder weapon may be presented to the eyewitness in an effort to determine whether he recognizes it.
According to Thomson and Tulving (1973), there is considerable controversy in the literature on the effectiveness of contextual cues on recognition accuracy; specifically, the to-be-remember stimulus itself is a powerful contextual cue. Environmental context effects have consistently failed to replicate when recognition memory is used as a measure and when recall is used as a measure (Thomson and Tulving, 1973). In the eyewitness situation it is the subject who determines whether the context will be encoded and defines what is stimulus and what is ground.
The cognitive interviewer, when encouraging witnesses to reinstate context, asks them about their beliefs and expectations about a given event. However, according to Thomson and Tulving (1973), it is not clear from the cognitive interview research how effective this instruction is for different witnesses, which is why some studies elicited at 47 percent increase in collected information (Clifford and George, 1992) and others elicited a 35 percent increase (Cutshall and Yuille, 1989).
My opinion and original hypothesis have been altered by the gathered information, as the empirical evidence and other collected research is insurmountable against the idea that the cognitive interviewing process increases the credibility of eyewitness testimony by decreasing memory error and confabulations. The only justifiable and reliable results elicited from any of the said studies were that the cognitive interviewing process only increases the amount of information received from eyewitnesses; it does not have any effect on credibility. References Bekerian, D. , Dennett, J. , Hill, K. , & Hitchcock, R. (1990).
Effects of detailed imagery on simulated witness recall. Paper presented at the second European Conference on Law and Psychology, Nuremberg, Germany. Bull, R. , & Memon, A. (1991). The cognitive interview: its origins, empirical support and practical implications. Journal of Community & Applied Social Psychology, 1, 291-307. Clifford, B. , & George, R. (1992). Making the most of witnesses. Policing, 8, 185-198. Cutler, B. , Martens, T. , & Penrod, S. (1987). Improving the reliability of eyewitness identifications: putting context into context. Journal of Applied Psychology, 72, 629-637. Cutshall, J. , & Yuille, J. 1989). A case study of eyewitness memory of a crime. Journal of Applied Psychology, 71, 291-301. Fisher, R. (1986). Client memory enhancement with the cognitive interview. Florida Bar Journal, 60, 53-56. Fisher, R. , Geiselman, R. , Holland, H. , & MacKinnon D. (1986). Eyewitness memory enhancement in the cognitive interview. American Journal of Psychology, 99, 386-401. Stewart, J. (1985). Interviewing witnesses and victims of crime. Research in Brief, US Department of Justice, p. 1. Thomson, D. , & Tulving, E. (1973). Encoding specificity and retrieval processes in episodic memory. Psychological Review, 80, 353-370.