C - Loftus and Palmer Flashcards
Aim (2)
- Looks at memory of eye witness testimony.
- wanted to see the effect leading questionshad on the memory of an event.
Background
- Memory involves interpreting what is seen or heard, recording bits of it and then reconstructing these bits into memories when required.
- This infers recall can be distorted or biased by certain features of the situation.
- Loftus and Palmer conducted many studies investigating ways in which memory can be distorted, many of which show that EWT is highly unreliable because it can be influenced by such things as subtle differences in the wording of questions.
- This study focuses on the effects of ‘leading questions’ on an individual’s ability to accurately remember events.
- The expectation was that any information subtly introduced after the event through leading questions – questions phrased in a way suggesting the expected answer – would distort the original memory.
Method
Experiment 1
- 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.
Experiment 2
- This was also a laboratory experiment using an independent measures design.
- The independent variable (IV) was the wording on a question in a questionnaire:
- One group was asked, “About how fast were the cars going when they smashed into each other?” - A second group was asked, “About how fast were the cars going when they hit each other?” - A third group was not asked about speed. - One week later, all participants were asked to complete another questionnaire which contained the critical question, “Did you see any broken glass?”
- The dependent variable (DV) was whether the answer to this question was, “Yes/No.”
Sample
Experiment 1
- 45 students were divided into five groups with nine participants in each group.
Experiment 2
- 150 students were divided into three groups with 50 participants in each group.
Procedure
Experiment 1
- All participants were shown the same seven film clips of different traffic accidents which were originally made as part of a driver safety film.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.
- There was one critical question in the questionnaire: “About how fast were the cars going when they hit each other?”
- One group was given this question while the other four groups were given the verbs “smashed’, ‘collided’, ‘contacted’ or ‘bumped’, instead of ‘hit’.
Experiment 2
- All participants were shown a one-minute film which contained a four-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.
Results
Experiment 1
- Smashed produced the fastest speed estimates and contacted the slowest.
Experiment 2
- 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.
Conclusions
- The verb used in a question influences a participant’s response ie the way a question is phrased influences the answer given.
- People are not very good at judging vehicular speed.
- Misleading post event information can distort an individual’s memory.
- It is proposed that two kinds of information go into our memory for a ‘complex occurrence’ such as this. Firstly, the information gleaned during the perception of the original event. Secondly, the post-event information that is gained after the fact. Information from the two sources will integrate over time and we will be unable to decipher which source the information comes from. We are therefore unable to tell whether our memory is accurate.
Method Evaluation
P: One strength of the research method is that it was a lab exp. conducted in a controlled environment.
E: This controlled E.V.s allowing cause and effect to be established. (IV had affected the DV) = high internal validity
E: For example, L&P used precise timings of the films, randomised the presentation of the question order, and included distractor questions. This ensured that the effect of leading questions on the speed estimate was accurately measured.
P: However it was artificial situation = low ecological validity E: the task carried out in the study is not realistic to real life – lacks mundane realism E; Car crashes will create more emotion if seen in real-life and would have more motivation to recall the speed more accurately so leading questions may have less of an impact.
Data
P: Not qualitative E: There was no opportunity to explain why P’s didn’t have the chance to say what they remembered about their experience of the car crash or why they estimated the speed as they did
Ethics
P: Minimal ethical issues E: P’s had right to withdraw, were protected from harm and were debriefed. E: Researchers showed films of staged car crashes that had been filmed for H&S training so this should not have upset students
P: Did not gain informed consent
E: didn’t tell them the aims
P’s were not fully aware of the aims – but they couldn’t be as this would have caused demand characteristics
Reliability
P: High control so easily replicable
E: clear standardised procedures and operationalised variables
E: The instructions were standardised, the car crashes were fully operationalised eg taken from a H&S video and the study is very easy to replicate.
Validity
P: High internal validity
E: highly controlled with an IV and DV
E: High control throughout the experiment – car crash clips, length of clips, questions asked etc. meant that L&P could be sure that they were measuring what they intended to measure
P: Low external validity – in particular ecological validity
E: not applicable to real life
The car crashes were watched in an artificial environment so lack realism – it is highly unlikely that anyone would watch a car crash like that in real life. The p’s may also have worked out the aim especially in experiment 2 so there could be demand characteristics
Sampling Bias
P: lacks representativeness and population validity
E: cannot generalise to the rest of the population as it was specific to just students
E: Students, so used to be tested on, unlikely to be drivers than the population on the whole so less good at estimating speeds, they are also younger which means that leading questions are more likely to have an impact.
Ethnocentrism
P: Only studied American students
E: based on only one culture – individualistic
E: Reflects only educated cognitive processes – students come from MC backgrounds on the whole and other people may perform differently The individualistic culture of America – concerned about themselves whereas people in collectivistic cultures are more influenced by the group
