Cognitive interview:

• STRENGTH:

  • Is evidence that it works
  • For example, a meta-analysis by Köhnken et al.

  (1999) combined data from 55 studies comparing the cognitive interview with the standard police interview

  • The cognitive interview gave an average 41% increase in accurate information compared with the standard interview
  • Only four studies in the analysis showed no difference between the types of interview

  This shows that the cognitive interview is an effective technique in helping witnesses to recall information that is stored in memory (available) but not immediately accessible
• LIMITATION:

  • Köhnken et al. also found an increase in the amount of inaccurate information recalled by participants
  • This was a particular issue in the enhanced cognitive interview which produced more incorrect details than the Cl. Cognitive interviews may sacrifice quality of EWT (i.e. accuracy) in favour of quantity (amount of details).

  This means that police officers should treat eyewitness evidence from Cls/ECIs with caution.
• LIMITATION:

  • not all of its elements are equally effective or useful
  • Milne and Bull (2002) found that each of the four techniques used alone produced more information than the standard police interview
  • But they also found that using a combination of report everything and reinstate the context produced better recall than any of the other elements or combination of them.
  • This confirmed police officers' suspicions that some aspects of the Cl are more useful than others.

  This casts some doubt on the credibility of the overall cognitive interview.