Loftus and Palmer

• How many experiments were conducted by Loftus and Palmer?

  Two experiments
• How many participants were in Experiment 1?

  45 participants
• How many participants were in Experiment 2?

  150 participants
• What type of design was used in Loftus and Palmer's experiments?

  Independent groups design
• What were the procedures in Experiment 1?


  • Shown 7 film clips of traffic accidents
  • Clips ranged from 5-30 seconds
  • Participants completed a questionnaire after each clip
  • Key question about speed with different verbs used
• What was the key question asked in Experiment 1?

  About how fast were the cars going when they ___ each other?
• What verbs were used in Experiment 1's key question?

  Hit, smashed, collided, bumped, contacted
• What were the procedures in Experiment 2 part 1?

  • Shown a film of a multiple car crash
  • Crash lasted less than 4 seconds
  • Asked questions including a critical speed question
  • Verbs used: smashed, hit
  • Control group had no critical speed question
• What was the critical question in Experiment 2 part 2?

  Did you see any broken glass?
• Was there any broken glass in the film shown in Experiment 2?

  No, there was no broken glass
• What were the findings of Experiment 1 regarding speed estimates?

  • Smashed: mean speed estimate 40.8
  • Contacted: mean speed estimate 31.8
• What were the findings of Experiment 2 part 1 regarding speed estimates?

  • Higher speed estimates in smashed conditions
  • Consistent with Experiment 1 findings
• What were the findings of Experiment 2 part 2 regarding broken glass?

  • Yes responses:
  • Smashed: 16
  • Hit: 7
  • Control: 6
  • No responses:
  • Smashed: 34
  • Hit: 43
  • Control: 44
• What conclusions can be drawn from Loftus and Palmer's findings?

  • Question form affects witness answers
  • Two explanations:
  • Response-bias factors
  • Memory representation alteration
• What are the strengths of Loftus and Palmer's methodology?

  • Standardised procedures
  • Results replicated consistently
  • Controlled experiment reduces confounding variables
• What are the weaknesses of Loftus and Palmer's procedures?

  • Lack of ecological validity
  • Participants may not take task seriously
  • Emotional response differs from real accidents
• What ethical concerns are associated with Loftus and Palmer's study?

  • No valid consent obtained
  • Participants unaware of study aims
  • Less distressing than witnessing a real accident