ewt: cognitive interview

• Fisher and Geiselman (1992) claim that EWT could be improved if the police use techniques based on psychological insights into how memory works. They called this the cognitive interview. Rapport is established with interviewee
• Report everything


  Witnesses are encouraged to include every detail of an event, even if it seems irrelevant. Seemingly trivial details could be important and may trigger other memories
• Reinstate the context


  The witness returns to the original crime scene ' in their mind ' and imagines the environment (weather,what they see) and their emotions (what they felt). This is based on the concept of context-dependent forgetting. Cues from context may trigger recall
• change perspective


  witnesses recall the incident from other people's perspectives. How would it have appeared to another witness or the perpetrator? This prevents the influence of expectations and schema on recall.
• Reverse the order


  Events are recalled in a different chronological order (e.g. from the end back to the beginning, or from the middle to the beginning). This prevents people using their expectations of how the event must have happened rather than the actual event. It also prevents dishonesty
• Enhanced cognitive interview


  Fisher et al. (1987) developed additional elements of CI. This includes social dynamics of the interaction (e.g. knowing when to establish and relinquish eye contact). The enhanced CI also includes ideas such as reducing the eyewitness's anxiety, minimising distractions, getting the witness to speak slowly and asking open-ended questions
• strength: some elements of the full CI are useful

  Milne + Bull (2002) found that each individual element of the CI was equally valuable. However, they also found that a combination of 'report everything' and 'context reinstatement' produced better recall than any of the other techniques individually. So at least these two elements should be used to improve police interviewing of eyewitnesses even if the full CI isn't used
• strength: effective


  Kohnken et al (1999) combined data from 50 studies. The enhanced CI consistently provided more correct information than the standard interview used by police. Studies like this indicate that there are real practical benefits to the police of using the enhanced version of the CI
• limitation : time consuming

  Police are reluctant to use CI because it takes much more time than the standard police interview. More time needed to establish rapport with the witness to allow them to relax. CI requires special training and many forces have not been able to provide more than a few hours
• limitation : produces incorrect info

  Kohnken et al found an 81% increase in correct information but also a 61% increase in incorrect information when the enhanced CI was compared to a standard interview. The increase in correct information implies that police should continue to use CI. However, the results also suggest that police need to treat all information collected with caution