EWT

• why is EWT so important


  the delvin report stated that in 1973 there were 850 criminal court cases where the only evidence of guilt was EWT and 75% of these led to a conviction
• what does the innocence project show


  EWT is the cause of 69% of wrongful convictions in the USA which were overturned by cost-conviction DNA evidence
• why might EWT not be reliable


  schemas
• what is a schema

  a cognitive framework that helps the interpret info

  
  

  eg a schema of a bank robber is a guy in a black and white shirt
• what is the theory of reconstructive memory


  by bartlett

  
  

  argues that memory isnt just a video playback of an event but an active process in recreating an event when recalling, when we have gaps in our memory we use info from our schemas to fill the gaps
• what 3 things affect EWT


  (misleading info)

  - leading questions

  - post event discussion

  
  

  anxiety
• how can EWT be improved


  the cognitive interview
• who came up with the cognitive interview


  fisher and geiselman
• what is the cognitive interview


  a form of interview that encourages witnesses to recreate the original scenario to recall more information in order to give the witness more cues to stored info
• what are the 4 stages to the cognitive interview


  report everything

  context reinstatement

  change perspective

  change order
• what happens in report everything


  the interviewer encourages the witness to report all details about the event even though these details may seem to be unimportant
• what happens in context reinstatement


  the witness trys to mentally recreate an image of the situation including details of the environment eg weather to see if any more info is remembered
• what happens in change perspective


  the witness tries to mentally recreate the situation from different points of view eg what another witness mightve seen
• what happens in change order


  the witness is asked to recall the scene in a different chronological order
• why is the cognitive interview effective


  it obtains maximum information from a witness while minimising the interviewers influence on his or her responces
• how does report everything improve accuracy of EWT


  links to the theory of retrival failure- memories are interconected with one another so the recollection of one item may then cue a whole lot of others
• how does context reinstatement improve accuracy of EWT


  links to theories of retieval failure- often people cannot acess memories that are there so they need contextual and state cues to trigger more memories
• how does change perspective improve accuracy of EWT


  promotes a more hollistic view of the event which may enchance recall + disrupts the effect of schemas on memory
• how does change order improve accuracy of EWT


  recalling events from different orders prevents pre-existing schemas to influence what you recall

  it can also be used to verify accuracy of what is recalled
• evaluation of the cognitive interview (positive)


  the cognitive interview is proven to be effective

  -shown by a meta analysis

  
  

  effective for witnesses of diff ages

  - evidence suggests both elderly and young children show improvements when using CI

  - suggests that the CI is a more effective tool when interviewing witnesses who are considered more unreliable
• the meta analysis of the cognitive interview

  by Kohnken et al

  - 53 studies

  - found that there was a 34% increase in the ammount of correct info recalled compared to the standard interview technique

  
  

  suggests that CI increases accessibility to stored info in memory and can improve accuracy
• evaluation of the cognitive interview (negative)


  there are criticisms of the studies in the meta analysis

  
  

  criticisms of the CI technique:

  - quantity improves not necessarily quality, ammount of accurate info increases 81% but also the ammount of inaccurate info increases by 61%

  - time consuming, takes time to train officers and a long time to implement so police tend to prefer the briefer standard interview

  - some elements are more effective than others, Milne and Bull found that the RE and CR components were the most effective which suggests the CO/CP are not useful for increasing EWT

  - suggests the CI needs to be revised
• criticisms of the meta analysis of the CI


  predominantly lab studies were used which lack ecological validity

  
  

  sample lacks population validity, they tend to use uni students who have better memory than the general population

  
  

  this means the CI may be less effective at improving EWT in real life crimes and with diff populations