Improving the accuracy of EWT: cognitive interview

• Eyewitness testimony

  Legal term given to the use of eyewitnesses in court to give evidence for the identity of someone who has committed a crime
• The cognitive interview was developed by Fisher and Geiseman (1992) based on Tulving’s encoding specificity principle.
• The cognitive interview is a method of interviewing eyewitnesses to help them retrieve more accurate memories. It uses four main techniques: report everything, reinstate the context, reverse the order and change perspective.
• reinstatement of context is when…

  • the interviewer encourages witness to mentally recreate the physical and psychological environment of the original incident.
  • it accesses both state (internal) and context (external) cues to make memories accessible.
• report everything is when…

  • the interviewer encourages witness to report every detail they can remember without interruption.
  • they should report every minor detail even if it might seem irrelevant 
  • memories are interconnected with one another so recollection of one memory could cue another 
• change order is when…

  • interview encourages witness to recall events in a different order
  • prevents your pre-existing schema influencing what you may recall
• change perspective is when…

  • interviewer encourages witnesses to change their perspective to someone else in order to aid their recall by asking them how a different witness may have seen the event 
  • this tries to disrupt our schema 
• A strength of the use of the cognitive interview to improve the accuracy of eyewitness testimony is that there is support for its effectiveness. For example, Geiselman et al. (1985) found that the cognitive interview procedure produced more accurate and detailed memories than the standard police interview, including those conducted under hypnosis, suggesting that the cognitive interview can be effective.
• A weakness of the use of the cognitive interview to improve the accuracy of eyewitness testimony is that it can be a very time-consuming and expensive process. This is because it requires the witness to be interviewed several times and the interviewer to be trained in the technique. This weakens the use of the cognitive interview as it may not be appropriate or possible where time constraints are a factor.
• A strength of the use of the cognitive interview to improve the accuracy of eyewitness testimony is that it has been found to be more useful than standard interviewing techniques. Kohnken et al (1999) conducted a meta-analysis of 55 studies and found that the CI improved the accuracy of EWT by 41% compared to a standard interview. This demonstrates the real practical benefits of using the cognitive interview.
• A weakness of the use of the cognitive interview to improve the accuracy of eyewitness testimony is that it is not a reliable method. This is because Kohnken et al. (1999) carried out a meta-analysis of 55 studies comparing the CI to the standard police interview and found that CI resulted in both more accurate detail and more inaccurate detail. This limits the cognitive interview as it brings into question its usefulness and accuracy.
• The enhanced cognitive interview was developed by Fisher et al and its features include:

  • No distractions or unnecessary interruptions or questions.
  • Flow of information controlled by the witness.
  • The use of open-ended questions, such as, ‘and then what happened?’
  • Witness to speak slowly.
  • Witness reminded not to guess and to reply with ‘don’t know’ when necessary - reduces the risk of false memories.
  • Interviewer to help reduce the anxiety of the witness.
• Holliday (2003) produced a modified version of enchanced cognitive interview for use with children. Holliday emphasised the building of trust between the interviewer and the witness, but removed the ‘change perspective’ to concerns that young children would find this too difficult.
• A shorter version of the CI and ECI are also used because of the time constraints experienced by many police forces who do not have the time to use the full version.
• A strength of the enhanced cognitive interview is that it has supporting evidence. For example, Fisher et al. (1989) found that the ECI produced superior results in comparison to the standard police interview. This strengthens the enhanced cognitive interview because it shows how effective it is and means that it could be beneficial to society.
• A strength of the enhanced cognitive interview is that it is suitable for a wide range of people. Holliday (2003) produced a modified version of the enhanced cognitive interview which did not include the ‘change perspective’ aspect. This was compared the standard police interview and it was found that the modified version produced more accurate results with groups of four to five and nine to ten year olds. This strengthens the use of the enhanced cognitive interview as it can be successfully used for all age groups.