loftus and palmer

• opportunity sampling

  using independent measures

  lab location

  IV = verb used

  DV = speed estimate or whether they saw broken glass
• experiment 1

  1. shown 7 films of traffic accidents
  2. asked to give account and answer questions eg ' how fast were they going when the cars;

  • smashed - hit - collided - bumped - contacted
• experiment 2

  • 150 students
  • 1 clip of multi car crash
  • asked if smashed - hit - no question
  • after 1 week asked if they has seen broken glass
• findings and conclusions of experiment 1

  • verb = mean estimate of speed (mph)
  • smashed = 40.8
  • collided = 39.3
  • bumped = 38.1
  • hit = 34
  • contacted = 31.8

  two possible results = response bias (misleads) or actual changes in memory
• findings and conclusions of experiment 2

  16 said yes in smashed vs 6 in hit

  shows questions altered memory so not response bias = leading questions = key words combine and change original memory
• replicable study = lab location and standardised procedures = can repeat to check for consistency = increases external reliability
• high control = lab location = controlled = same crashes shown = cause and effect more easily established = increases internal validity
• sample bias = only students = may be less experienced drivers = worse guessers = low population and external validity = not generalisable
• supporting evidence = 7% saw 'a' broken headlight vs 17% 'the' broken headlight = supports idea that leading questions can alter memory
• ethical = cars traveling at moderate speeds vs real crash = reduce risk of harm as protected from stress and anxiety
• lack valid consent = true aim not revealed = invalid consent = deception = unethical
• social implication in court = greene = mock jury aware of mistakes = more skeptical = damaging as could be correct key evidence
• social implication for justice = avoid leading questions using cognitive interviews = more trust and accuracy