EWT Flashcards
Eye witness testimony
The ability of a person to remember details of an event they have observed
Mainly used for crimes / accidents
Accuracy of EWT can be affected by leading questions + anxiety and other factors
What is a leading question
A question in which, because of the way it is
phrased, suggests a certain answer.
These can have a negative effect on EWT and can seriously alter accuracy of a persons recall of events
Loftus + palmer 1974 procedure
45 students.
Shown video clips of road traffic accidents. After each clip Ps asked to give an account of the accident.
They were then split into 5 groups with 9
participants in each group.
All of the participants were asked: ‘About how fast were the cars going when they ________ into each other’ (smashed, hit, bumped etc)
Participants estimates were recorded in miles per hour (mph)
Loftus + palmer findings
Smashed - estimated 40.8 mph
Collided - estimated 39.3 mph
Bumped - 38.1
Hit - 34
Contacted - 31.8
Leading questions clearly influence perception of speed with participant speed estimates for the word ‘smashed’ being almost 10mph faster than for the word ‘contacted’
Why do leading Qs affect EWT
1. Response bias
The wording of a question has no real effect on a persons memories but just influences how they decide to answer
When a participant gets a leading question with ‘smashed’ it encourages them to estimate a higher speed
Why do leading Qs affect EWT
2. substitution
the wording of a question actually changes a person’s memory of an event
it will alter the way we remember the event affecting the way we might give an EWT.
loftus + palmer follow up study
150 students watched a short video (multi car accident)
Ps split into 3 groups - 50Ps each
group 1 - “how fast were they going when they hit each other?”
group 2 - how fast were the cars going when they smashed into each other
group 3 - not asked about speed of vehicles
followed up after 1 week - “Did you see any broken glass?” - there wasn’t any!
loftus + palmer follow up study findings
16 people who said yes were asked using the word smashed
44 people who said no were in the control group
what is post event discussion
occurs when there is more than 1 witness to an event
those who have observed the event will discuss what happened with other co-witnesses
post event discussion can influence accuracy of EWT
Gabbert et al procedure
Pairs of participants (students and older adults) each watched a different film clip of the same crime so each had a unique view of the event
Pairs were able to discuss what they had witnessed before carrying out a recall test of the event seen in the video
Gabbert et al findings
71% of eyewitnesses who had discussed the crime made mistakes when recalling the events
In pairs where no discussion had taken place 0% of mistakes in recall were made
This suggests that PED can lead to inaccurate eyewitness testimony
Strength of misleading info - useful
P: One strength is that research into the effects of misleading information has been useful.
E: This research has been useful in developing questioning techniques e.g. The Cognitive Interview that the police will use when gathering EWT. It attempts to minimise the use of leading questions for example, so you are more likely to gather a reliable EWT.
Strength of misleading Qs - lab exp
P: studies that support misleading Qs on EWT is that they are conducted in a lab - Loftus + palmer
E: EVs can be controlled. Use of standardised procedures eg. All Ps watch the same video
C: this allows a C+E relationship to be established eg. A leading question with a harsher word eg smashed in causes a higher estimated speeds in
Limitation of misleading info - tasks given
P: can criticise tasks used in supportive studies eg Loftus + palmer
E: Ps were asked to estimate speed of car after watching a video clip. However in real life there would be more anxiety as the crash would happen in front of you so your estimate speed may differ
C: this means it lacks mundane realism. So we can’t generalise findings real life so you don’t know much about EWT in real life
limitation of studies supporting misleading info - conducted in lab
anxiety
Johnson + Scott
J+S findings
yuille + cutshall
Y + C findings
yerkes dodson law
eval
eval
eval
eval
improving accuracy of EWT - cognitive interview
a method of interviewing eye witnesses to help them retrieve more accurate memories/info
based on 4 main techniques thought to help recall and improve accuracy of EWT
4 techniques used in cognitive interview
1. report everything
witnesses encouraged to include every detail of the event even if it doesn’t feel relevant
trivial details may be important and could trigger other memories
4 techniques used in cognitive interview
2. reinstate context
witnesses should return to original crime scene ‘in their mind’ and imagine the environment and their emotions - related to context dependent forgetting
4 techniques used in cognitive interview
3. reverse the order
events should be recalled in diff order from original sequence. this prevents people reporting their expectations of how the event must have happened rather than reporting actual events
also prevents dishonesty
4 techniques used in cognitive interview
4. change perspective
witnesses should recall the incident from other people’s perspectives.
this is done to disrupt effect of expectations and the effect of schema on recall
enhancement of cognitive interview
Fisher et al (1987) added extra elements to cognitive interview - enhanced cognitive interview (ECI)
these include:
1. focus on social dynamics between interviewer and interviewee eg. eye contact
2. ways to reduce anxiety , distractions, speech rate + use of open end Qs
strength of cognitive interview - supportive research
P: supportive research for effectiveness of CI
E: over 50 studies have found that you collect more accurate EWTs from CI in comparison to standard police interview
C: EWTs will be more accurate so only the guilty will get convicted rather than innocent people so there is justice.
strength of cognitive interview - useful
P: all factors of EWT are useful eg. report everything
E: found that police don’t need to use all 4 factors of the cognitive interview to gather more reliable details. instead, they can choose just one or 2 factors and still gather more reliable testimonies compared to standard interview
C: accuracy of EWT still improved using smaller scale version of CI
limitation of cognitive interview - requires training
P: time consuming and expensive (requires training)
E: police force may opt for standard interview due to lack of funding
C: so some police forces may be using methods that are less reliable, reducing accuracy of EWT.
limitation of cog interview - not reliable
P: CI may not be as reliable as it claims
E: a study showed that whilst CI improves accuracy of info recalled, there can also be an increase of inaccurate info being recalled (81% accurate vs 61% inaccurate)
C: can have a negative effect on legal system as some info is still inaccurate
