Improving accuracy of eyewitness tesimony : Cognitive interview

Cognitive interview

A method of interviewing eyewitnesses to help them retrieve more accurate memories. It uses four main techniques , all based on evidence based psychological knowledge of human memory - report everything, reinstate the context, reverse the order and change perspective.

Report everything

Witnesses are explicitly told to include every single detail of the event, even if it feels trivial or lacks certainty. Seemingly minor details can act as critical cognitive cues to trigger other important, hidden memories.

Reinstate the context

Witnesses are asked to mentally return to the original crime scene. They imagine the environment (e.g., weather, visual surroundings) and their internal emotional state at the time, which actively prevents context-dependent forgetting.

Reverse the order

The events are recalled in a different sequence from how they naturally occurred (e.g., from the final moments backward to the beginning). This prevents witnesses from reporting structural expectations or stereotypes of how the event should have happened, while also making dishonesty harder to maintain.

Change perspective

Witnesses recall the incident from alternative viewpoints, such as how it would have appeared to other bystanders or to the perpetrator. This step is designed to disrupt the distorting effects of personal schema on recall, which naturally creates false expectations about specific settings.

Whats the enhanced cognitive interview

Fisher et al. (1987) updated the original model by adding elements focused on the social dynamics of the interaction. These improvements include: Asking targeted, open ended questions, reducing eyewitness anxiety, encouraging witness to speak slowly.

Support for the effectiveness of CI

A meta-analysis by Köhnken et al. (1999) of 55 studies showed that the CI provides a 41% increase in accurate eyewitness information compared to standard police interviews, proving it effectively unlocks inaccessible memories.

Counterpoint: However, Köhnken et al. also found an increase in the amount of inaccurate information recalled, especially in the Enhanced CI (ECI). The interview can sacrifice overall quality/accuracy in favor of quantity, meaning police must treat this evidence with caution.

Some elements may be more useful

Milne and Bull (2002) discovered that while each individual CI technique outperformed standard interviews, a specific combination of report everything and reinstate the context produced the highest recall rates. This confirms that certain aspects of the CI carry more utility than others, casting doubt on the necessity of the complete model.

The CI is time - consuming

A major practical limitation is that the complete CI demands significantly more time and specialised training than forces can afford. Extra time is needed to establish rapport and help a witness relax, and Kebbell and Wagstaff (1997) noted that most police forces lack the resources to provide more than a few hours of training. This suggests using the full CI is unrealistic, and officers should focus on just a few key components instead.