Loftus and Palmer

Loftus and Palmer

1. The aim of this study was to investigate how information supplied after an event, influences a witness's memory for that event.

2. The study actually consists of two laboratory experiments. They are both examples of an independent measures design. The independent variable in both of the experiments is the verb used. The dependent variable in the first experiment is the participant?s speed estimate and the dependent variable in the second experiment is whether the participant believed they saw glass.

3. The participants were 45 students of the University of Washington. They were each shown seven film-clips of traffic accidents. The clips were short excerpts from safety films made for driver education. The clips ranged from 5 to 30 seconds long.

4. Following each clip, the students were asked to write an account of the accident they had just seen. They were also asked to answer some specific questions but the critical question was to do with the speed of the vehicles involved in the collision.

5. There were five conditions in the experiment (each with nine participants) and the independent variable was manipulated by means of the wording of the questions.

   • Condition 1: 'About how fast were the cars going when they smashed into each other?'
   • Condition 2: 'About how fast were the cars going when they collided into each other?'
   • Condition 3: 'About how fast were the cars going when they bumped into each other?'
   • Condition 4: 'About how fast were the cars going when they hit each other?
   • Condition 5: 'About how fast were the cars going when they contacted each other?'
   • In each condition, a different word or phrase was used to fill in the blank. These words were; smashed, collided, bumped, hit, contacted.

6. ·

   • 1. Firstly, they argue that the results could be due to a distortion in the memory of the participant. The memory of how fast the cars were travelling could have been distorted by the verbal label which had been used to characterize the intensity of the crash.
   • 2. Secondly, they argue that the results could be due to response-bias factors, in which case the participant is not sure of the exact speed and therefore adjusts his or her estimate to fit in with the expectations of the questioner. (This is also an example of a demand characteristic)

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