7. Factors Affecting Accuracy of EWT - Misleading Info

• 1. Factors Affecting Accuracy of EWT - Misleading Info

  Factors Affecting EWT:

  • Leading Questions.
  • Misleading Info.
• 2. Factors Affecting Accuracy of EWT - Misleading Info

  Loftus + Palmer (1974):

  • 45 Americans.
  • Car crash video; asked speed of car.
  • Manipulated verb used.
• 2a. Factors Affecting Accuracy of EWT - Misleading Info

  Loftus + Palmer (1974) - Results:

  • Smashed - 40 mph.
  • Collided - 39 mph.
  • Bumped - 38 mph.
  • Hit - 34 mph.
  • Contacted - 31 mph.
• 3. Factors Affecting Accuracy of EWT - Misleading Info

  Loftus + Palmer pt2:

  • 150 students.
  • 1 min video; asked if saw broken glass.

  Results:

  • ‘Smashed’ = 32% broken glass.
  • ’Hit’ = 14% broken glass.
  • Control group = 12%.
  • No broken glass, ‘smashed‘ more likely report broken glass, leading question.
• 3a. Factors Affecting Accuracy of EWT - Misleading Info

  Leading Question Affecting EWT:

  • Response-Bias Factor = influences answer given.
  • Substitution Explanation = verb changes perception.
• 4. Factors Affecting Accuracy of EWT - Misleading Info

  Gabbert et al. (2003) - Post-Event Discussion:

  • Witnesses discuss details of crime.
  • Pairs participants, each watched video same crime (diff perspectives).
  • All pairs discussed what seen + recall test.
  • 71% mistakenly recalled aspects they didn’t see but picked up in discussion.
  • Control group, 0%.
• Factors Affecting Accuracy of EWT - Misleading Info (Evaluation)

  Strength:

  P - real-life application, criminal justice system.

  E - Loftus, leading questions distorting effect memory = police must be careful phrasing questions.

  E - psychologists act as experts witnesses in trials to explain EWT to juries.

  L - improvement of legal system, protect innocent from faulty convictions based on unreliable EWT.
• Factors Affecting Accuracy of EWT - Misleading Info (Evaluation)

  Limitation:

  P - Loftus + Palmer’s (1974) participants watched in lab, diff to witnessing IRL crime.

  E - what they watched didn’t have critical effect on real-world events so could be less motivated to be accurate.

  L - lack external validity + internal validity.
• Factors Affecting Accuracy of EWT - Misleading Info (Evaluation)

  Limitation:

  P - post-event discussion alters EWT.

  E - Skagerberg + Wright (2008), film clip; one version dark brown hair; other hair light brown.

  E - discussed in pairs; didn’t report what seen or what heard from co-witnesses but blend of both.

  L - memory distorted through contamination by misleading post-event discussion, not memory conformity.
• Factors Affecting Accuracy of EWT - Misleading Info (Evaluation)

  Limitation:

  P - misleading info = inaccurate EWT due to control variables.

  E - Zaragoza + McCloskey (1998), answers given by participants in lab studies = demand characteristics.

  E - want to be helpful to researcher so guess.

  L - lowers internal validity of lab study findings, meaning can’t refer to them IRL.