In this study Loftus and Palmer are attempting to demonstrate that memory is not a factual recording of an event and that memories can become distorted by other information which occurs after the event.
To see the effect of leading questions on the memory of an event
Experiment 1 - Sample
- 45 students of the University of Washington
- Split into 5 groups of 9
Experiment 1 - Procedure
- Laboratory Experiment
- Independent Measures Design
- They were each shown seven film-clips of traffic accidents
- The clips ranged from 5 to 30 seconds long.
- Following each clip, the students were asked to write an account of the accident they had just seen.
- IV - The verb in the critical question
- DV - Estimate of the speeds
- There were five conditions in the experiment:
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.
Experiment 1 - Results
- Verb & Estimation of Speeds:
- Smashed: 40.8 mph
- Collided: 39.3 mph
- Bumped 38.1 mph
- Hit 34.0 mph
- Contacted 31.8 mph
- Estimate of the cars speeds did vary according to the verb used in the crictical question
- 'Contacted' got the lowest estimate and 'Smashed' got the highest.
Experiment 2 - Sample
- 150 participants
- Split into 3 groups of 50
Experiment 2 - Procedure
- Participants viewed a short (one minute) film which contained a 4 second scene of a multiple car accident
- There were three conditions:
- 'How fast were the cars going when they hit each other?'
- 'How fast were the cars going when they smashed into each other?'
- Control group (One set of participants weren't asked about the speed of vehicles)
- One week later, the participants returned and, without viewing the film again, they answered a series of questions about the accident.
- The critical question was 'Did you see any broken glass?'
- There was in fact no broken glass in the film.
Experiment 2 - Results
Response to the question 'Did you see any broken glass?'
- 'Smashed' Yes = 16, No = 34
- 'Hit' Yes = 7, No = 43
- 'Control' Yes = 6 No = 44
- These results show that the verb (smashed) in the question did have a significant effect on the mis-perception of glass in the film.
- Those participants that heard the word ?smashed? were more than twice as likely to recall seeing broken glass.
There are 2 types of info which make up a memory:
- Information we get from percieving an event
- Information we get after the event eg. questions asked.
Key Evaluation Points
- High levels of control
- Low ecological validity
- Consent Gained
- Possible distress
- Easy to analyse
- Easy to compare
- Restricted views
Improvements/ Changes & Implications
An actual car crash with dummies
- Ethically sound
- Low ecological validity
- Diverse - representative
- High reliability