(7) Unit 1 - Classic Research: Loftus and Palmer (1974) - Restruction of Automobile Destruction (methodologies and procedures)

How many experiments were completed?

2 - Experiment 1 and Experiment 2.

Where was the experiment conducted?

In a laboratory.

What experimental design was used?

An independent groups design.

What was the independent variable in both experiments?

The verb used within the leading question.

What was the dependent variable in Experiment 1?

The estimate of speed.

What was the dependent variable in Experiment 2?

Whether the participants saw broken glass.

How many students were used in Experiment 1?

45 - 9 participants per group.

How many students were used in Experiment 2?

150 - 3 groups of 50 participants, one of which was a control group.

What was the aim of Experiment 1?

To see if people’s memories can be influenced by words used by interviewers after an event (post event information).

What did participants watch in Experiment 1?

7 health and safety clips of different car accidents, ranging from 5-30 seconds.

What were participants asked to do after watching the video in Experiment 1?

To ‘give an account of what you have just seen’. They then answered more specific questions about the video, the critical question being: ‘about how fast were the cars going when they _______ into each other?’. The space was filled by one of five verbs: ‘smashed’, ‘hit’, ‘collided’, ‘bumped’ or ‘contacted’. Nine participants were asked each verb condition.

What was recorded based on the questionnaire in Experiment 1?

The participants’ estimate of speed.

What were participants shown in Experiment 2?

A film of a multiple car crash. The film lasted less than a minute; the actual accident lasted less than 4 seconds.

What were participants given after watching the videos in Experiment 2?

They were given a questionnaire. The first question asked them to describe the accident in their own words. 50 participants were asked ‘how fast were the cars going when they smashed into each other?’, 50 participants were asked ‘how fast were the cars going when they hit each other?’, and the final 50 participants were in a control group and were not exposed to any question.

What happened a week after watching the video in Experiment 2?

The participants returned and answered various questions about the accident. The critical question that all participants were asked was ‘did you see any broken glass?’. There was no broken glass in the accident, but since broken glass is associated with high-speed accidents, the smashed condition were expected to say ‘yes’ more often.