Loftus And Palmer

Loftus And Palmer

1. Experiment 1

   • Method
     • Laboratory Experiment
     • Independent measures
   • Aim
     • To investigate the effects of leading questions on an individual's ability to accurately remember events
   • Participants
     • 45 students
     • 5 conditions with 9 participants in each
   • Apparatus
     • 7 film segments
       • From Evergreen Safety Council of the Seattle Police Department
       • Lasted between 5 and 30 seconds
       • 4 were staged so speed was known
     • 7 Questionnaires
       • "Give and account of the accident"
       • "About how fast were the cars going when they.....?"
         • Verb at the end changed for each group
         • Contacted/Hit/Bumped/Collided/Smashed
   • Results
     • People are not very good at judging how fast a vehicle is actually travelling
       • Estimate : 37.7mph
       • Actual speed ; 20mph
     • The verb in the question affected the eye witness answers
       • Smashed ; 40.8mph
       • Contacted : 31,8mph
   • Disscussion
     • Two possible explanations for findings
       • Due to repose bias factors
       • The form of the question causes a change in memory

2. Experiment 2

   • Method
     • Laboratory Experiment
     • Independent Measures
   • Participants
     • 150 students
     • 3 groups 50 participants in each
   • Aim
     • To investigate whether memory would be reconstructed as a result of information received after the event
   • Apparatus
     • A film showing a multiple car accident
     • 2 questionnaires
       • Carried out on the day
         • Describe the accident
         • "How fast were the cars going when they.....?"
           • Hit
           • Smashed
           • Control group were not asked about speed
       • Carried out 1 week later
         • 10 questions
         • "Did you see any broken glass?"
   • Results
     • Wording had an effect on speed estimation
       • Smashed : 10.46mph
       • Hit : 8mph
       • The verb effects whether glass was thought to have been seen or not
         • Smashed : 16 said yes
         • Hit : 7 said yes
         • Control: 6 said yes
   • Discussion
     • Explanation
       • Two kinds of information create a memory
         • Information obtained at the event
         • Information supplied after the event
         • Merge to create one memory
       • Reconstructive Hypothesis

3. Evaluation

   • Validity
     • highly controlled and standardised
       • Establish cause and effect
       • High design validity
       • May have suffered demand charecteristics
       • Low ecological validity
   • Reliability
     • Procedure highly standardised
       • Re-done to test reliablilty
     • Two experiments
       • Results supported each other
   • Ethics
     • Hypothesis was concealed
       • Deception
       • Avoided demand characteristics
     • All safety films
       • Did not cause distress
   • Data
     • Quantitative
       • Easily compare across conditions
       • Easily summariesed
   • Sample
     • Only students
       • Cannot generalise
       • Narrow age range
       • Students are more obedient so may be more willing to comply
   • Ethnocentrism
     • Investigating a behaviour shown in all humans
     • Only reflect the cognitive processes of educated/ upper class people

4. Usefulness

   • Used by Police
   • Leading questions not allowed in court
   • Not easy to change memory

5. Links to area/perspective

   • Cognitive area
   • Cognitive process of memory

6. Links to key theme

   • Evidence on how memory is effected by information after an event
   • Effects of language on memory