Misleading information - EWTs

• the response bias expanation 


  wording of a question has no effect on an ews memory of an event but can influence the kind of answer given
• substitution explanation

  wording of a question does affect eye witness memory ; it interferes with its original memory, distorting its accuracy.
• post-event discussion (PED)

  memory contamination and memory conformity
• memory contamination

  when co-witnesses discuss a crime, the mix (mis)information from other witnesses with their own memories
• memory conformity

  witnesses go along with each other to win social approval or because they believe the other witnesses are right.
• Loftus and Palmer - leading questions procedure

  45 student participants watched videos of car accidents and then answered questions about speed. critical question: "about how fast were the cars going when they [...] each other?" There were five groups that were each given a different 'key' word; hit, bumped, contacted, collided, smashed.
• Loftus and Palmer - leading questions findings 


  the verb 'contacted' produced a mean estimated speed of 31.8mph. for the verb 'smashed', the mean was 40.5mph.
• Loftus and Palmer - leading questions conclusion

  the key verb biased eye witness recall of an event. the more violent the verb the faster the cars were said to go.
• Gabbert et al. - post event discussion procedure

  paired participants watched a video of the same crime, but filmed so each participant could see parts the other could not. both participants discussed what they had seen before individually completing a recall test.
• Gabbert et al. - post event discussion findings


  71% participants mistakenly recalled aspects of the video they hadn't seen but had picked up in the PED
• Gabbert et al. - post event discussion conclusion

  in a control group, where there was no discussion, there were no errors.
• limitation of loftus and palmer's study

  used artificial materials. participants watched film clips and not actual events - creates a very different experience than a real life accident. yuille et al. found that EWTs were still accurate 4 months after a traumatic event. shows that using artificial tasks tells us little about how leading questions actually affect EWTs
• strength of Loftus and Palmer on leading questions

  research into misleading questions is good RWA. the research had led to important practical uses for police investigations as consequences of inaccurate EWTs can be dangerous. tells police officers that they need to be careful to not use leading questions. means psychologists can make a real improvement to the lives of people - improving the legal system