Loftus and palmer 1974

Question 1

aims

Answer 1

to investigate the effects of leading questions on the accuracy of participants recall. this is order to see whether eyewitness testimony can be affected by post event info which implies it could be unreliable.

Question 2

experiment 1

Answer 2

procedure-
45 American students formed an opportunity sample
- lab experiment with 5 conditions, only one of which was experienced by each participants- independent
- 7 films of traffic accidents were presented in random order
- after watching, they were asked specific questions including the question about’ about how fast were the cars going when they ‘ collided, bumped, contacted, smashed, hit each other’
the IV was the wording of question and DV was the estimate speed reported by them

results- smashed had the highest mean estimated speed in miles per hour 41
conclusions-
a change of word could significantky affect a witness answer for two reasons;
they were uncertain of the speed and the verb used created a bias and influenced their decision
- the wording causes a change in memory of accident, so they recall it being more severe

Question 3

experiment 2

Answer 3

procedure-
150 students were shown a one minute film which included a car accident
-3 conditions;
1. 50 asked how fast were they going when hit
2. how fast were they going when they smahsed
3. not asked to estimate
after a week they were called back and were questioned again on accident and asked ‘ did you see any broken glass’

results - the people who were asked smash gave an estimate of 10mph and more of them than the other groups had seen glass.
hit was 8 mph and 43 had not seen broken glass
control 6 said yes to glass but 44 said no
conclusions- the post event info did not simply create a response bias. it altered the persons memory of the event and generated expectations.

Question 4

generalisability

Answer 4

:) both male and female used so no gender bias
:( students were used so the findings might not be generalisable to the whole pop. perhaps students have different motivation when participating and therefore their memory for events may be better. this means that the sample is not representative and so we cannot be sure the same results about leading questions would be found for diff people, making it lack external validity.

Question 5

reliability

Answer 5

:) lab exp so had clear controls- they all watch the same film of crashes and asked identical questions. except for verb change iv
therefore its replicable and can be tested again to check for consistency

Question 6

validity

Answer 6

:) lab so had high controls over extraneous variables.
eg. they all watched the same clip for the same amount of time in a controlled room and were asked the same questions. this means we can be sure it was the manipulation of the IV that caused the change in the DV increasing the internal validity.
:) data gathered was quant so easy to analyse and with minimal subjective interpretation.

:( watching a video of a car accident is not reflective of a real life situation as they watched a clip of a car crash rather than experiencing it. therefore the study lacks ecological validity, meaning that the EWT accuracy found in thus study can not be applied to typical everyday accounts.

Question 7

ethics

Answer 7

:) watching a video of a crime is less likely to cause stress and psych harm than being a witness to a real crime for the purpose of research.
:( study did not get fully informed consent. they were unaware of the critical question or the fact that the verb had been manipulated.