Loftus & Palmer Eyewitness Testimony

Loftus & Palmer Eyewitness Testimony

1. Schema theory proposes that memory is influenced by what an individual already knows, and that their use of past experience to deal with a new experince is a fundemental feature of the way the human mind works. the schema forms part of Barlett's theory of reconstructive memory which forms the basis for Loftus & Palmer's study into Eyewitness Testimony.

2. Background of the study

   • Memory involves interpreting what is seen or heard, recording bits of it then constructing these bits into memories when required. This infers recall can be distorted or is biased by certain features of the situation.
   • Loftus and Palmer conducted many studies investigating ways in which memory can be distorted, many of which show that eyewitness testimony is highly unreliable because it can be influenced by such things as subtle differences in wording if questions
   • This study focuses on the effects of leading questions on an individual's ability to accurately remember events.
     • The expectation was that any information subtly introduced after the event through leading questions - questions phrased in a way suggesting the expected answer - would distort the original memory.

3. Research Method

   • Experiment 1 - was a lab experiment using an independent measures design. The IV was the wording of a critical question hidden in a questionnaire. This question asked " About how fast were the cars going when they hit / smashed / collided/ contacted / bumped into each other?
     • The DV was the estimated speed given by the participant.
     • Experiment 2 - was also a lab experiment using an independent measures design.
       • The IV was the wording of a question in a questionnaire : one group were asked " About how fast were the cars going when they smashed into each other? " A second group were asked " About how fast were the cars going when they hit each other ? ". A third group was not asked about the speed.
         • One week later all the participants were asked to answer another questionnaire which contained the critical question " Did you see any broken glass? ". The DV was whether the answer was Yes or No.
   • Sample
     • EXPERIMENT 1 - 45 students were divided into 5 groups with 9 participants in each group. EXPERIMENT 2 - 150 students were divided into 3 groups with 50 participants in each group.
       • Procedure
         • Experiment 1 - All participants were shown the same 7 film clips of different traffic accidents which were originally made as a part of a driver safety film. after each clip participants were given a questionnaire which asked them firstly to describe the