loftus and palmer

• What was the aim?

  To test their hypothesis that language used in eyewitness testimonies can alter memory
• What was the sample?(Experiment 1)

  45 students

  divided into 5 groups of 9
• What was the method? (Experiment 1)

  Lab experiment

  using independent measures design

  IV: the verb used in critical questions ("How fast were the cars going when they ______ each other?") (hit, smashed, collided, contacted, bumped)

  DV: the estimated speed given by each ppnt
• What was the procedure? (Experiment 1)

  All ppnts watched the same 7 clips of a traffic accident which was made for a driver safety video

  After each clip ppnts were given a questionnaire to describe the accident and answer questions about it

  The critical question was "How fast were the cars going when they _______ each other?"

  Each group had a different verb from "hit, smashed, contacted, collided and bumped"
• What were the results for experiment 1?

  The estimated speed decreased with the severity of the verb

  Smashed was given the highest estimated speed

  Contacted was given the lowest estimated speed
• What was the sample? (Experiment 2)

  150 students

  divided into 3 groups (smashed, hit or no question)
• What was the method? (Experiment 2)

  Lab experiment

  using independent measures design

  Only ppnts from the hit and smashed conditions were used

  IV: verb used in questionnaire

  DV: answer to the questions "Did you see any broken glass"
• What was the procedure?(Experiment 2)

  All ppnts watched a 1 min clip of multiple 4 sec car crash

  After watching the clip ppnts were given a questionnaire and asked to describe the accident and asked "How fast were the cars going when they smashed/hit each other?"

  The control group had no question about vehicular speed

  After one week the ppnts were given another questionnaire, without seeing the clip again

  The critical question was "Did you see any broken glass" - there was no glass in the video
• What were the results in experiment 2?

  More people in the smashed condition reported seeing glass
• What were the conclusions?

  The verb used in a question can influence ppnts response

  People aren't very good at estimating vehicular speed

  Misleading post-event information can distort memory

  We do not know if memory is accurate. This is because the initial information of the original event will eventually integrate with the post-event information gained. So we do not know which source our information comes from.