methodology and procedures

• aim

  loftus and palmer (1974): reconstruction of automobile destruction - wanted to investigate in general how accurate or inaccurate memory was.

  specifically, they wanted to see how the effect of leading questions upon estimates of speed.
• the study consists of two experiments conducted in a laboratory using an independent groups design.

  each experiment was conducted with a different set of participants.
• experiment 1: 45 US college students

  experiment 2: 150 US college students
• EXPERIMENT 1 IV


  verb used to describe the collision
• EXPERIMENT 1 DV


  estimate of speed provided by the participants
• EXPERIMENT ONE

  • they were shown 7 clips of traffic accidents ranging from 5-30 seconds.
  • after each clip, participants filled in a questionnaire, giving a general account of what they had seen along with a series of specific questions about the accident.
• EXPERIMENT ONE - CRITICAL QUESTION


  • the critical question was the one that interrogated them about the speed of the vehicle:
  • "About how fast were the cars going when they _ each other?"
  • the words in the blank space varied from group to group - 9 subjects were given hit, and equal numbers of remaining participants were given the verbs smashed, bumped, collided and contacted.
  • participant estimates were in miles per hour.
• EXPERIMENT TWO

  • they were shown a film of a multiple car crash that lasted 4 seconds.
  • the participants then filled in a questionnaire, giving a general account of what they had seen, as well as a series of questions including the critical question about speed.
  • participants were divided into three groups of 50:
  • group 1 = smashed
  • group 2 = hit
  • group 3 = control group - the members were not exposed to any question.
• EXPERIMENT TWO

  • one week later, the participants returned, and without reviewing the film again, were asked a series of questions about the car accident.
  • the critical question: "Did you see any broken glass?"
  • there was no broken glass in the film.
• EXPERIMENT TWO IV


  the verb used to describe the collision.
• EXPERIMENT TWO DV 


  the recall of broken glass (yes or no.)