Loftus & Palmer Flashcards
What were the independent variables in L&P’s experiments?
Experiment 1: verb used in the critical question “about how fast were the cars going when they ***** each other”, this word was either ‘hit’, ‘contacted’, ‘bumped’, ‘collided’ or ‘smashed’
Experiment 2: whether the verb ‘smashed’ or ‘hit’ was in the critical question
What was the aim of L&P’s study?
Overall: whether the phrasing of questions about a car accident could alter participants memory of an event
First experiment: investigate the effect of question phrasing on witness memory of a car crash
Second experiment: establish where memory’s of participants were actually distorted by the phrasing of the question, by seeing if a false memory of broken glass was created in the ‘smashed’ condition
What were the dependent variables in L&P’s experiments?
Experiment 1: the mean estimated speed of the car
Experiment 2: whether the participants’ claimed to see broken glass false memory
What were the controls in L&P’s experiments?
Experiment 1: no control
Experiment 2: one group was not asked about the speed of the car crash
In L&P’s study what method was used?
Experiment 1+2: laboratory experiment, using independent measures design
What was the procedure for L&P’s experiments?
Experiment 1: 45 students shown 7 films of car crashes. 4 films were staged and speeds were know at, 20, 30, 40 and 40mph. After watching all participants were asked to write an account and then asked questions, all were fillers except the critical ‘about how fast were the cars going when they _____ each other’, changing the verb for each of the five conditions, either hit, bumped, collided, contacted or smashed was used. A mean speed was collected for each condition
Experiment 2: 150 students, split into 3 groups of 50, all watched a video of a car crash lasting under a minute, they were then given a questionnaire asking questions one to describe the incident, other fillers and the critical question ‘about how fast were the cars going when they ____ each other’ 50 participants had the verb ‘hit’, 50 had the verb ‘smashed’ and 50 controls had no question on speed. A week later 10 more questions were asked, the critical question was ‘did you see the broken glass’ (note, there was no broken glass in the film), the yes/no answers from all groups were recorded and made into a table
What were the findings in L&P’s study
Experiment 1: we are poor at estimating speed, film 1s speed was out by 17.7mph. Verbs effect estimations on speed with smashed as the greatest mean speed (40.5mph) and contacted at the lowest (31.8mph)
Experiment 2: when the verb smashed was used people estimated the cars speed to be faster at 10.46mph compared to the hit condition at 8mph and over two times more people in the smashed condition reported broken glass than the hit condition (16) hit was (7)
Conclusions of L&P’s study
- Response bias. When a participant is unclear what speed to estimate the verb gives them a clue as to where there estimate should be high or low
- Memory distortion. The verb used in the question actually alters a participants memory of the crash
What was L&P’s hypothesis before their study?
It was a two tailed hypothesis, they thought there were factors other than the actual speed of a car which influence out judgement
Outline the ethics in L&P’s study
Ethics were good there were few ethical issues, possibly harm and distress from realising they’re poor memory or witnessing a crash
What participants were used in L&P’s experiments
Experiment 1: 45 students, 5 groups of 9, smashed, hit, bumped, collided, contacted
Experiment 2: 150 students, split into 3 groups of 50, smashed, hit, control
What was the participant design in L&P’s experiments
Both were opportunistic samples, with a independent measures design, meaning that separate groups of participants do different levels of the I.Vs
