Loftus and Palmer (1974)

Question 1

Aim

Answer 1

To study the effectiveness of eyewitness testimony from Bartlett’s theory of reconstructive memory.

Question 2

Experiment 1 Sample

Answer 2

45 students were divided into five groups with nine participants in each group.

Question 3

Experiment 2 Sample

Answer 3

150 students were divided into three groups with 50 participants in each group.

Question 4

Experiment 1 Procedure

Answer 4

This was a laboratory experiment using an independent measures design.

The independent variable (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 each other?”

The dependent variable (DV) was the estimated speed given by the participant in mph

All participants were shown the same 7 film clips of different traffic accidents which were originally made as part of a driver safety film.

After each clip participants were given a questionnaire which asked them firstly to describe the accident and then answer a series of questions about the accident.

Question 5

Experiment 1 Findings

Answer 5

Verb Mean speed estimate (mph)
Smashed 40.8
Collided 39.3
Bumped 38.1
Hit 34.0
Contacted 31.8

Smashed produced the fastest speed estimates and contacted the slowest.

Question 6

Experiment 2 Procedure

Answer 6

All participants were shown a one-minute film which contained a 4-second multiple car crash.

They were then given a questionnaire which asked them to describe the accident and answer a set of questions about the incident.

There was a critical question about speed:
– One group was asked, “About how fast were the cars going when they smashed into each other?”
– Another group was asked, “About how fast were the cars going when they hit each other?”
– The third group did not have a question about vehicular speed.

One week later, all participants, without seeing the film again, completed another questionnaire about the accident which contained the further critical question, “Did you see any broken glass – Yes/No?” There had been no broken glass in the original film.

Question 7

Experiment 2 Findings

Answer 7

a) Speed estimates for the verbs used in the question about speed

More participants in the ‘smashed’ condition than either the ‘hit’ or control groups reported seeing broken glass.
The majority of participants in each group correctly recalled that they had not seen any broken glass.