Loftus And Palmer Flashcards
What area is this study
Cognitive area
What is the key theme
Memory
What is the aim of the study
To investigate the effect of leading questions on eye witness testimony of car crashes
Research method ?
Lab experiment
Independent measures design
What is the independent variable
The verb used
Contacted/ hit/ bumped/ collided/ smashed
What is the dependent variable
The estimate of speed
Whether the ppt saw glass
How many ppts were in experiment 1
45 students
How many groups were the students/ ppts divided into in experiment 1
The 45 students were divided into 5 groups
What was the procedure of experiment 1
The students watched 7 film clips of car accidents from driver safety training films
After watching the films the students were asked to do two things :
Write an account of what they had seen
Answer questions on what they had seen
One question was the critical question - about how fast were the cars going when they (verb) eachother
What were the 5 conditions( verbs) in the experiment
Contacted Hit Smashed Collided Bumped
Results of the speed estimates for the verb smashed
40.8 mph
Results of the speed estimate for collided
39.3
Results of the speed estimate for bumped
38.1mph
Results of the speed estimate for hit
34 mph
Results of the speed estimate for contacted
31.8 mph
Results for the 4 staged films where speeds were accurately measured
The film of a crash at 20mph was estimated to be 37.7mph
The film of a crash at 30mph was estimated to be 36.2mph
The films of crashes at 40mph were estimated to be 39.7mph and 36.1
Conclusion of experiment 1
How the question was phrased influenced the participants speed estimates
When the verb smashed was used, ppts estimated that the cars were travelling much faster than when the verb ‘contacted’ was used
People are not very good a judging vehicular speed
What were Loftus and palmers 2 explanations for experiment 1
1) response bias- the critical word makes ppts think they should answer in a particular way
2) memory is altered - the critical word changes a persons memory do they actually ‘ see’ the accident differently
How many ppts were in experiment 2
150 students
What was the procedure for experiment 2
Students watched a one minute film which showed a 4 second multiple car accident
After the film, the participants were divided into three experimental groups
What were the three experimental groups asked
Group 1 - ‘how fast were the cars going when they HIT eachother
Group 2 - ‘how fast were the cars going when they SMASHED INTO eachother ?
Group 3 - was asked NO QUESTION about the speed of the cars
One week after the experiment (experiment 2) the ppts were asked to return. A critical question was asked, what was the question
“Did you see any broken glass?”
There was no broken glass in the film
What were the results of the critical question
Twice as many ppts in ‘smashed’ group said they saw broken glass compared to ‘hit’ or control group
‘Smashed’ - 16 ppts said they saw glass
‘Hit’- 7 ppts said they saw glass
Control- 6 ppts said they saw glass
Conclusion of experiment 2
Leading questions had actually altered the ppts memory of the event
Loftus and Palmer sugggest that two kinds of information go into a persons memory for an event:
Firstly, the persons own perception at the time of the event, and secondly information supplied after the event
