factors affecting the accuracy of EWT

Question 1

What is an EWT?

Answer 1

This is the ability of a person to remember details of an event they have observed.
Mainly used for accidents & crimes.
The accuracy of EWT can be affected by various factors such as leading questions & anxiety.

Question 2

What’s misleading information?

Answer 2

Incorrect or suggestive information given to the witness after the event.
This can be in many forms like post-event discussion or leading questions.

Question 3

What are leading questions?

Answer 3

A question in which, prompts a desired response by the way in which it is phrased. E.g., was the accused wearing Nike Trainers? - this suggests that they were!
Leading questions can have a negative effect on EWT and can seriously alter the accuracy of a person’s recall of events. This can be quite serious especially if you are asked to testify in court.

Question 4

What did Elizabeth Loftus do and find?

Answer 4

How frequently do you get headaches?
How occasionally do you get headaches?

People who were asked how frequently they got headaches reported an average of 2.2 headaches per week.

People who were asked how occasionally they got headaches reported an average of 0.7 headaches per week.

Question 5

What did Harris (1963) do and find?

Answer 5

How tall was the basketball player?
How short was the basketball player?

People who were asked how tall was the basketball player gave an average of 79 inches.

People who were asked how short was the basketball player gave an average of 69 inches.

Question 6

What did Loftus and Palmer do?

Answer 6

45 students.
Shown video clips of road traffic accidents. After each clip participants were asked to give an account of the accident. They were then split into 5 groups with 9 participants in each group. Viewed same 7 video clips of car accidents originally made as part of a driver safety film - 3 were real, 4 were staged. The staged crashes were used to show what can happen to humans when cars collide at different speeds. They were asked to give an account of the accident then were asked a series of questions including a critical question…… About how fast were the cars going when they each other?
Participants estimates were recorded in miles per hour (mph)
Smashed
Hit
Bumped
Collided
Contacted

Question 7

What did Loftus and Palmer find?

Answer 7

Leading questions clearly influence perception of speed with participant speed estimates for the word ‘smashed’ being almost 10mph faster than for the word ‘contacted’.

Question 8

Why do leading questions affect EWT?

Answer 8

Explanation 1: Response-bias
The wording of a question has no real effect on a person’s memories but just influences how they decide to answer.
When a participant gets a leading question with the word “smashed” in, it only encourages them to estimate a higher speed.

Explanation 2: Substitution
The wording of a question actually changes a person’s memory of an event.

Question 9

What did Loftus and Palmer do in their follow-up study?

Answer 9

150 students watched a short video (multi car accident).
Participants split into 3 groups (50 participants in each).

all viewed same 1 minute film showing a 4 second multiple car crash then given a questionnaire which asked them to describe the accident and answer a set of questions.
There was a critical question about speed:
- ‘About how fast were the cars going when they smashed into each
other?’
- ‘About how fast were the cars going when they hit each other?’
The third group did not have a question about 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 and broken glass – Yes/No?” - there had been no broken glass in the original film.

Question 10

What did Loftus and Palmer find in their follow-up study?

Answer 10

P’s that heard the word “smashed” were more likely to report broken glass (there wasn’t any) than those why heard the word “hit.”
Loftus & Palmer follow-up study supported the substitution explanation. They found that the wording of a question actually changes a person memory.

Question 11

What’s post event discussion?

Answer 11

This occurs when there is more than one witness to an event.
Those who have observed the event will discuss what has happened with other co-witnesses.
Post event discussion can influence the accuracy of EWT.

Question 12

What did Gabbert et al (2003) do and find?

Answer 12

Filmed a variety of videos of a crime from different angles, meaning each participant saw something slightly different, for example one person could see the title of a book that a young woman was carrying but others couldn’t. participants only saw one variation of the video and participants were allowed to discuss what they had seen before being tested for recall.

71% of participants mistakenly recalled aspects of the video that they did not see but picked up in the discussion. In a control group with no discussion 0 mistakes were made. Witnesses will go along with one another to gain approval or because they genuinely believe that the other witness is correct, and they are wrong.

Question 13

What are the strengths of Loftus and Palmer’s study?

Answer 13

ONE STRENGTH OF LOFTUS AND PALMER IS THAT THE RESEARCH WAS CONDUCTED IN A LAB SETTING.
E – DESCRIBE EXTRANEOUS VARIABLES L+P COULD HAVE CONTROLLED AND THE STANDARDISED PROCEDURES USED.
C – WHAT CAN WE THEREFORE ESTABLISH, AND WHAT WERE L+P ABLE TO DO DUE TO THE STANDARDISED PROCEDURES/CONTROL USED IN THE RESEARCH, AND WHY IS THAT BENEFICIAL?

The research into the effects of misleading information on the accuracy of EWT has been extremely useful.
E- Give a result from L+P….. We now understand the consequences of this; in the real world inaccurate EWT can be serious and can lead to inaccurate convictions.
C- Strength because it highlighted the importance of how police officers word their questions when gathering EWT from witnesses and lead to the development of the cognitive interview.
Why is this beneficial and how could this impact the economy in a positive way?

Question 14

What are the limitations of Loftus and Palmer’s study?

Answer 14

ONE PROBLEM IS THE SAMPLE THAT L+P USED IS UNREPRESENTATIVE AND CANNOT BE APPLIED UNIVERSALLY.
E - WHAT ARE THE ISSUES WITH THE SAMPLE THAT L+P USED FOR THEIR RESEARCH ON EWT? TIP: THINK AGE, STUDENTS, DRIVING EXPERIENCE
RHODES 2006 FOUND ACCURACY DIFFERENCES IN GROUPS OF PEOPLE AGED 18-25 AND 55-78.
C – DESCRIBE WHY THIS IS AN ISSUE IN REGARD TO THE IMPACT OF LEADING QUESTIONS.

One problem is that L+P’s research is conducted in a highly controlled, artificial environment.
E - Write down differences between what L+P’s PP’s experienced and how this is different to real life eyewitnesses experience. E.g. use of video
C – Describe why this is an issue in regard to ecological validity.
Eval Extra – how might demand characteristics have been shown in L+P’s research

Question 15

What is anxiety?

Answer 15

A state of emotional and physical arousal including having worried thought or feelings and physical changes such as heart rate increase which can impact accuracy of memory.

Question 16

What did Johnson and Scott (1976) do and find when researching anxiety: negative effect on recall?

Answer 16

Participants thought they were taking part in a laboratory study - seated in a “waiting room” and all participants heard an argument coming from the next room.

Condition 1 (low anxiety group) - a man left the room with a pen & grease on his hands.
Condition 2 (high anxiety group) - a man left with a knife and blood on his hands.
Had to identify the man from a set of 50 photos.

Only 33% of participants in the high anxiety group were able to correctly identify the man with a knife & blood on his hands.
49% of the participants in the low anxiety group were able to correctly identify the man with a pen & grease on his hands.
Tunnel theory & Weapon Focus: witnesses’ attention is drawn towards the weapon, as it’s a source of anxiety which has a negative/detrimental effect on EWT.

Question 17

What did Yuille and Cutshall (1986) do and find when researching anxiety: positive effect on recall?

Answer 17

Conducted a study of a real life shooting in Vancouver- the shopkeeper shot the thief dead.
Total of 21 witnesses - 13 agreed to take part in study. Interviewed 4-5 months after event - compared to their original accounts at time of incident. Also asked to rate stress levels and if they had experienced any emotional problems since.
Accuracy: number of details reported in each account.

Witnesses were very accurate in their accounts - little change in accuracy levels. Some minor details less accurate e.g., colour of items etc.
Those who reported highest levels of stress were most accurate (88% most stressed vs. 75% for less stressed) which supports the idea that anxiety can have a positive impact on recall of events.

Question 18

What are the findings over the effect on recall on anxiety?

Answer 18

Some research suggests that anxiety causes the accuracy of EWT to be impaired/reduced but other contradictory research suggests that anxiety causes the accuracy of EWT to become more accurate.

Question 19

What’s Yerkes-Dodson Law?

Answer 19

Lower levels of anxiety= lower EWT accuracy.
Memory becomes more accurate, as anxiety increases until it reaches an optimal point. This is when EWT are most accurate. However, there becomes a point in which the anxiety levels become too high, and accuracy begins to reduce.

Question 20

What is a strength of factors affecting EWT: anxiety?

Answer 20

MANY OF THE STUDIES ARE DONE IN A FIELD EXPERIMENT. LINK BACK TO A STUDY. WHY IS THIS GOOD? CAN YOU COUNTER ARGUE THIS IN ANYWAY?

Question 21

What are the limitations of factors affecting EWT: anxiety?

Answer 21

IS IT ETHICAL TO PUT PEOPLE IN SITUATIONS WITH HIGH LEVELS OF ANXIETY? WHAT ETHICAL ISSUE IS THIS BREAKING? WHAT EVIDENCE CAN YOU USE? WHAT ARE THE ISSUES WITH THIS?

ARE THEY ACTUALLY TESTING WEAPON FOCUS? USE PICKEL 1998 FROM THE VIDEO, WHAT DID THEY DO AND FIND? IF THEY’RE NOT REALLY TESTING WHAT THEY AIM TO WHAT DOES THIS LACK?

IS THE INVERTED U TO SIMPLISTIC? EVERYONE EXPERIENCES DIFFERENT EMOTIONS AND THOUGHTS UNDER ANXIETY AND THIS ISN’T CONSIDERED. ONLY CONSIDERS THE PHYSICAL AROUSAL LEVELS.