Factors affecting accuracy of EWT: misleading information

• 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
• Eyewitness memory


  Term psychologists use when carrying out research to test the accuracy of eyewitness testimony
• Factors affecting the accuracy of eyewitness testimony: misleading information including leading questions, post-event discussion and anxiety. Improving the accuracy of eyewitness testimony including the use of the cognitive interview
• Eyewitness Testimony


  • https://www.youtube.com/watch?v=cIfkMBDn9ZI
• Misleading information


  Information that occurs after an event that can easily change the memory of the event
• Leading questions


  A type of question that prompts a respondent towards providing an already-determined answer
• Leading questions


  • How fast were the cars going when they hit into each other?
  • How fast were the cars going when they bumped into each other?
  • How fast were the cars going when they collided into each other?
  • How fast were the cars going when they smashed into each other?
  • How fast were the cars going when they contacted each other?
• Loftus and Palmer study on leading questions

  1. 45 students were shown 7 films of different traffic accidents

  2. After each film, participants were given a questionnaire to complete involving questions about the accident

  3. The critical question involved the speed of the car

  4. A different verb was used for each group
• Loftus and Palmer found that the word used affected the speeds recalled by each group
• Loftus and Palmer's second study showed that leading questions don't just give a biased answer from the witness, they actually change their memory of the event
• Post-event discussion


  When there is more than one witness to an event, they may discuss what they have seen with each other, or with other people that weren't there, which may influence the accuracy of each witnesses' recall of the event
• Anxiety


  A state of emotional and physical arousal, including worries, thoughts, feelings, tension, increased heart rate, breathing rate and sweating
• Johnson & Scott study on anxiety

  1. Participants were placed in either a low anxiety or high anxiety condition

  2. Participants witnessed a different scene whilst sitting in the waiting room

  3. All participants were then asked to identify the man from 50 photographs
• Johnson & Scott found that 49% of participants from the low anxiety condition were able to correctly identify the man compared to only 33% from the high anxiety condition
• Weapon focus effect


  When a person is experiencing high anxiety, they focus all of their attention on the weapon instead of any other details, making recall difficult
• The Cognitive Interview


  1. Report everything

  2. Mental reinstatement

  3. Change perspective

  4. Change order
• Milne and Bull found that using a combination of 'report everything' and 'mental reinstatement' significantly increased recall compared to a normal interview
• Kohen et al found a 34% increase in accuracy in recall when using the Cognitive Interview compared to a standard interview