Factors affecting accuracy of eyewitness testimony Flashcards
what is misleading info?
supplying info that may alter memory
who are the key experimneters?
Palmer and Loftus (1974)
what is the aim of the experiment 1?
aimed to show that leading questiones could distort EWT, have a confabulating effect (producing false memories) , and so one will be distroted by cues provided in the question.
what is the procedure of the experiment 1?
- 45 American students of uni of Washington
- opportunity sample
- lab
- 5 conditions
- independent group design
- 7 films, 5-30 sec, were presennted to each group in a random order
- after watching ppts had to describe what happend as if they were eyewitnesses
- asked specific questions including ‘How fast were the cars going when they smashed/collided/bumped/hit/contacted?’
- IV= wording
DV= estimated speed
what is the findings of the experiment 1?
speed was effected by the wording
info about speed affected memory of accident
smaashed=fastest
hit=slower
what is the aim of the experiment 2?
to test whether ppts alter their answres when the wording of the question changes due to repsonse bias OR altering their memory
what is the procedure of the experiment 2?
- 150 students
- 1 min film
- 4 sec traffic accidenet
- questioned
- IV = wording
- 50 students - ‘How fast….hit?’
- 50 students - ‘How fast…smashed’
- 50 students - no question
- 1 week later - measured DV asked question w/o watching film
- ‘did you see any broken glass?’
what is the findings of the experiment 2?
those who were asked about speed were likely to say they did
* there was no glass in a film
what is post-event discussion
conversation between an eyewitness and interviwer after a crime has taken place, it may contaminate witness’s memory about the event
how does Post-event discussion affect EWT? (also found by whom?)
by Loftus
* Collage students who visited Disneyland when they were children
* asked to evaluate advertising material about diesneyland, the material contained misleading info about Bags Bunny (not a disney character)
* Ppt who were in a group with Bugs Bunny, were more likely to say they rememver them form Disneyland, and that they shook hands with them
* while control group didnt have such a high rate
eval 1 top
loftus sauggests that in general accuracy of EWT is very low, and therefore it is unreliable
and the research was criticised having low ecol val
eval 1 point
however, in real life EWT is very accurate
which means Lab experiment is lacks ecol val, as the results dont reflect real life
Yuille and Cutshall
found that when a real eobbery happened nearly all eyewitnesses could correctly identify the criminal even after 4 months later
even if they were given 2 leading questions
eval 1 tail
suggesting missleading info m ay have less influence on real life EWT than Loftus has described
therefore the thory looses its usefulness in application
eval 2 top
However, it is still being good at improving criminal justice systme , that relies havily on eyewitness identification for investigativing
eval 2 point
this research has been used to warn justice system, and to address the problem of blaming an innocent
Recent DNA exoneration (blaming smn mistakanely) cases have confirmed that mistaken EWT was the largest single factor that contributes to the conviction of innocent people
eval 2 tail
demonstrating the importance of the role of EWT on justice system, it helps to ensure that innocnt people are not blamed for crimes that they didnt commit,
eval 2 double
additionally contributing to the economy, as mistakes in legal justice system are costly
thereofre research into EWT will help to prevent from that
eval 3 top
however another criticicsm was that EWT is influenced by extraneous variables such as indiv diff
eval 3 point
was found in several studies that elderly people have overall difficulty to remember the info, even tho their memory of event is unimpaired (not damaged),
therefore there are more prone to the effects of misleading info when giving testimony
eval 3 tail
suggesting indov dif are important when measuring EWT
specifiically the age affects the DV
additionally, the eperiment by Palme3r and Loftus, included only students which is quite a limited sample to be generalised,
consequently it results in ‘wrong’ resluts for people who are in a dif age zone
