Loftus And Palmer Flashcards
Background of the Loftus and Palmer, 1974, eyewitness testimony study
Research into memory
Memory does not simply record what happens .
Certain questions/statements leader person to give a particular answer. Such statements are called leading questions.
Aims of the Loftus and Palmer, 1974, eyewitness testimony study
Experiment one-to test the effect of leading questions on recall
Experiment. Two -to see if a leading question changes a person subsequent memory of the event.
Design method of Loftus and Palmer’s, 1974 study on eyewitness testimony
Laboratory experiment, independent measures design
Experiment one was a snapshot study (one time frame) repeated measures.
Experiment two was longitudinal over one week.
Iv -experiment, one and, two = the verb(smashed)
DV -experiment, one= estimate of speed.
Experiment. Two = participants said they saw broken glass.
Sample of Loftus and Palmer’s, 1974 study on eyewitness testimony
Experiment one-45 US College students in five groups.
Experiment Two - 150 US students in three groups.
Materials/Apparatus
Experiment one= seven brief film clips of car accident plus questionnaire.
Experiment. Two = one minute film of a four second multiple car accident
Procedure of Loftus and Palmer’s, 1974 study on eyewitness testimony
Experiment one-
Participants were asked to describe the accident and answer questions, including one critical question “ how fast were the cars going when they(inserted verb) each other?
There were five different verb conditions = HIT, CONTACTED, SMASHED, BUMPED AND COLLIDED.
Participants were asked (on the questionnaire) to estimate the car speed in miles per hour(MPH)
Experiment Two =
Part one; participants were asked to describe the accident and answered questions about the film, including critical questions.
Three Groups of participants =
Experimental group 1 -the verb was (SMASHED)
Experimental group, 2 -the verb was (HIT)
Control group (group, 3) - there was no question.
Part 2-participants return to the lab a week later.
They were asked further questions about the film clips, e.g. “ did you see any broken glass?”(that was not any broken glass in any of the film clips.)
Results of Loftus and Palmer’s, 1974 study on eyewitness testimony
Experiment 1. -
Meanspeed estimates were faster for the “ smashed” group(40.5 mph) then the” contacted“. group(31.8mph)
Mean speed estimates for the others were ; collided(39.3 mph)
Bumped(38.1 mph) and hit(34.0 mph)
Participants were poor estimating speed actual speeds and clips were 20, 30, 30, and 40 mph, but participants mean estimates were between 36 and 40 MPH
Experiment. Two
Means speed estimates were faster for those who had the verb smashed (10.46) mph Than those with the verb hit.(8.0 mph)
More participants who had the verb smashed reported seeing broken glass (16 out of 50 participants) then other participants
Seven (out of 50.) participants with the verb (hit )and six(out of 50) in the control group reported, seeing broken glass
Overall, most participants correctly reported seeing no broken glass (121 out of 150)
Conclusions of Loftus and Palmer’s, 1974 study on eyewitness testimony
Experiment one-the way of question is asked influence the answer given.
Experiment Two -such questions influence a memory that is stored rather than just play biasing a person’s response.
Two types of information make up our memory of a complex event-information from my perception of the event and the information we receive after the event.
Research, methods and techniques
+ laboratory conditions mean, extraneous variables can be controlled so high internal validity, e.g. in real life, estimates of speed might be affected by where a person is standing in a laboratory. We can ensure that each participant witness the accident from the same position.
-watching films is not the same as watching a real accident so participants lack emotional involvement foster et al (1994) found that people in real accidents are likely to remember more.
-The study involves a task that people are not good at estimating the speed of a moving vehicle
Reliability
+ quantitative data is relatively straightforward to access the reliability of the measurements that are made
could ask the same participants to repeat the task and second time and would expect to get the same speed estimates each time
Sampling bias of Loftus and Palmer’s, 1974 study on eyewitness testimony
+ opportunity, sample of US students, and degree courses that were easy for researchers to obtain
-Students have unique characteristics(e.g. more intelligent, and have better memories than the average person) so might be less likely to be affected by leading questions. This research may underestimate the effect of leading questions..
Types of data
+ quantitative data-the estimates of speed and number of yes or no answers. Search data produces simple conclusions, but fairly superficial.
+ qualitative data-following each film, the participants received the questionnaire asking them to “give an amount of the accident. You have just seen “providing greater detail.
Ethical considerations
-Informed consent not obtained from participants. If participants were aware of the aim, they would have been aware that the question were leading and been more careful in the response they gave.
+ deception was relatively mild, no psychological harm and health, collect important data about the inaccuracy of eyewitness testimony.
Ethnocentrism
-America is an individual culture, which might affect the willingness of people to be influenced by leading questions.
-People from collectivist cultures may be more influenced by what other people say, as they value the links within a group more than individual needs.
