Factors Affecting Accuracy of EWT: leading questions

• Bartlett


  believed that memory doesn't work accurately like a camera but it's vulnerable to inaccuracies and interpretations based on our previous experiences

  so memories are reconstructed based on our expectations of schemas.

  schemas are our ready-made expectations which help us to understand our world.

  we use schemas to help us 'fill in the gaps' in our knowledge and simplify the processing of info
• a: Loftus and Palmer - accuracy of EWT

  A: look at the effect of leading questions on the accuracy of eyewitness testimony

  P: students watched film clips of car accidents + gave them questions about the accident

  critical questions (leading question) was about speed

  there were 5 groups and each group has a different verb in the place of 'hit' (contacted, bumped, collided, smashed)

  F: the mean estimated speed was calculated for each group e.g. 'smashed' = 40.5mph

  'collided' = 39.3mph

  'bumped' = 38.1mph

  'hit' = 34mph

  'contacted' = 31.8mph

  C: leading questions bias EWT of an event
• b: Loftus and Palmer: substitution explanation

  A: did a study to support substitution explanation

  P: they showed ppts film clips of car accidents and changed the verb in the critical question again

  this time, they also asked them to say it they recalled seeing broken glass or not

  F: those in the 'hit' were less likely to report seeing broken glass than those who hear 'smashed', even though there was no broken glass

  C: concluded the leading question/critical verb actually altered their memory of the event
• Response Bias


  suggests the wording of the question has no real effect on memory but just influences how they occur
• Substitution Explanation


  suggests the wording of the question actually changes the memory of the event
• Weakness - lack of ecological validity

  factors affecting accuracy of EWT may have limited real-life application due to fact that research such as Loftus and Palmer was done in a lab setting. This means the variables were highly controlled so a very different experience of what a real eye witness to a crime would experience.

  e.g. watching a video clip of a car accident is much less stressful than watching a real car accident and the impact of their testimony is reduced in a lab setting.

  furthermore, ppts knew they would be asked questions about the accident, which may not be the case in a real-life situation if the event is unexpected.

  there would also be far less distractions in a lab environment compared to a real-life incident.

  limits the ecological validity of research into misleading information's effect on EWT
• Weakness - lacks population validity

  Loftus and Palmer's research into misleading info may be criticised as lacking population validity.

  their original research used 45 students as a sample but it may be that this isn't representative of the target population.

  may be that students have unique memory abilities as they frequently use their memory for exams, they may also be at an advantage due to their age and much younger or older people might not perform the same as them on memory tests

  Therefore, it's difficult to generalise the findings of this research
• Weakness - individual differences

  age differences between real eye witnesses which weren't present in the original sample. research shows that an eye witness typically acquires information from 2 sources; observing the event itself and from subsequent suggestions.

  several studies have shown that compared to younger people, elderly people have difficulty remembering the source of their info, even thought their memory for the info itself is fine.

  As a results, they're more prone to the effect of misleading info when giving EWT.

  Findings reduces the reliability of Loftus and Palmer's research
• Strength - practical applications

  the consequence of inaccurate EWT can be very serious and if Loftus' research shows how leading questions can distort memory, it means that police officers should be careful to avoid any leading questions when interviewing eyewitnesses.

  furthermore, psychologists are sometimes asked to explain the limits of EWT to juries at court

  This shows that psychologists and their research into EWT can help to improve the legal system and minimise the chances of innocent people being wrongly convicted based on inaccurate EWT