Factors affecting the accuracy of EWT

• Identify the three factors affecting the accuracy of eyewitness testimony.


  Leading questions and post-event discussion (both types of misleading information).

  Anxiety.
• Outline research into leading questions as a factor affecting EWT.


  Research has found that leading questions affect the accuracy of EWT because they are phrased in a way to suggest a certain answer, and this answer may not be correct.

  E.g. one piece of research involved presenting university students with video clips of cars colliding before being asked to estimate the speed at which they were travelling.

  However, before being asked to estimate the speed, the participants were asked the key question: How fast were cars going when they ___ each other?
• Outline research into leading questions as a factor affecting EWT.


  Each group was given a different verb to fill in the blank. These included: smashed, collided, bumped, hit or contacted.

  The research found that the verb 'smashed' resulted In the fastest estimate of speed while the verb 'contacted' resulted in the slowest estimate of speed.

  This suggests that the verb used created a leading question e.g. the verb 'smashed' misled participants into saying the cars were travelling faster than they were. 
• Outline research into post-event discussion as a factor affecting EWT. 


  Research has found that post-event discussion can lead to innacurate eyewitness testimonies due to two reasons: memory contamination and memory conformity.

  Memory contamination refers to when eyewitnesses discuss what happened and, because their memory may be affected by their own biases and schemas, they may alter others’ memories into thinking they had witnessed things they actually didn't.
• Outline research into post-event discussion as a factor affecting EWT.


  Memory conformity refers to when witnesses discuss what happened and this leads some to go along with the others (even if they think they are wrong) for social approval.

  E.g. one piece of research involved participants watching a video of a girl whereby some participants witnessed the girl stealing money from a wallet while others did not.
• Outline research into post-event discussion as a factor affecting EWT.


  They were then either allowed to engage in post-event discussion or were kept alone before being tested on their recall.

  They found that the majority of those who were allowed to engage in post-event discussion recalled the girl stealing the wallet, even though half of them did not actually witness this. This therefore demonstrates that post-event discussion can decrease the accuracy of eyewitness testimony.
• Outline research into anxiety as a factor affecting EWT.


  Laboratory research has found that when participants experience high levels of anxiety, their eyewitness testimonies are less accurate.

  For example, in one study, participants heard a discussion in a room before a man came out carrying either: a pen with grease on his hands, or a knife with blood on his hands.
• Outline research into anxiety as a factor affecting EWT


  They found that more participants were able to correctly identify the man from a photo line-up when he was seen holding a pen than when he was seen holding an anxiety-inducing knife. This is due to the weapon-focus effect i.e. the knife creates feelings of anxiety so witnesses overly focus on the weapon rather than other details (e.g. the criminal’s face).

  However, real-life eyewitness cases have found that when witnesses experience high levels of anxiety, their eyewitness testimonies are more accurate.
• Outline research into anxiety as a factor affecting EWT.


  Witnesses to a real-life armed robbery were interviewed months after the crime whereby they were asked to rate how anxious they felt and what they had witnessed. They found that that those who reported being the most anxious produced the most accurate testimonies.

  This can be explained by the Yerkes-Dodson law which proposes that low or extreme levels of anxiety impairs recall while moderate amounts of anxiety improves recall.
• Evaluate research into leading questions as a factor affecting

  EWT: criticised for exaggerating their effects.

  This is because university students, who typically have limited driving experience, took part in the car crash study. This is a limitation because it could be argued that the verb did not actually alter their memories. Instead, because they had limited driving experience, they just relied on it to provide an estimate of speed. This means that other groups (e.g. older adults with more driving experience) would have been less affected by the leading questions asked.
• Evaluate research into leading questions as a factor affecting

  EWT: supporting evidence.

  For example, in a later replication of the car crash study, participants were also asked whether they had seen any broken glass in the video clips of the cars colliding. They found that participants who were originally given the verb 'smashed' were most likely to report seeing broken glass, even though there wasn't any. This is a strength as it shows that the verb used in the leading question did actually alter participants' memory of the incident.
• Evaluate research into leading questions as a factor affecting

  EWT: conducted in artificial environments.

  The car crash study was conducted in a controlled laboratory setting. Participants would have known they were just taking part in research and were not witnessing a real crime where there could be legal consequences when giving their testimony.

  They may be less likely to carefully consider their testimonies and so are more likely to be influenced by leading questions. This means that leading questions may not have such a significant effect in real life cases.
• Evaluate research into leading questions as a factor affecting

  EWT: involved the use of artificial tasks.

  Car crash study involved participants watching staged video clips of two cars crashing. This is a limitation because such tasks will not cause participants to feel the emotional distress that they would typically feel if they were a witness to a live crime. As a result, because of the lack of emotion in this research, participants may be more misled by the leading questions. Again this means that loading questions may not have such a significant effect in real life eyewitness cases.
• Evaluate research into post-event discussion as a factor affecting EWT: conducted in artificial environments.

  The study of the girl stealing/not stealing the wallet was conducted in a controlled laboratory setting. This is a limitation because participants would have known they were just taking part in research and were not witnessing a real crime where there could be legal consequences.

  They were less likely to carefully consider their testimonies and so would be more likely to be influenced by post-event discussion.
• Evaluate research into post-event discussion as a factor affecting EWT: involved the use of artificial tasks.

  Research involved participants watching a staged video clip of a girl stealing/not stealing a wallet. This is a limitation because such tasks will not cause participants to feel the emotional distress that they would typically feel if they were a witness to a live crime. As a result, participants may be more misled by the post-event discussion. This means that post-event discussion may not have such a significant effect in real life cases.
• Evaluate research into post-event discussion as a factor affecting EWT: practical applications.

  E.g. the finding that post-event discussion can negatively impact recall has resulted in police offers minimising opportunities for witnesses to discuss what they had seen with one another. This Is a strength because such changes in police practice have helped to improve the accuracy of eyewitness testimonies, thus maximising the chances of a successful conviction.
• Evaluate research into anxiety as a factor affecting EWT: weapon focus effect may be due to surprise rather than anxiety.

  Witnesses may have paid too much attention to the weapon due to its unusualness rather than due to anxiety.

  Participants watched a video of a thief entering a hairdressing salon carrying one either: scissors, a gun, a wallet or raw chicken. They found that participants' testimonies were poorest when the thief was holding the gun and the raw chicken. This is a limitation because it suggests that it may be surprise rather than how anxiety that affects recall.
• Evaluate research into anxiety as a factor affecting EWT: affected by confounding variables.

  This is because those who reported the highest level of anxiety were closer to the robbery and so this may have improved their testimony in comparison to those who were less anxious/further away. This is a limitation because it means it is difficult to establish whether the differences in the accuracy of their recall was due to their position during the incident or the level of anxiety they felt.
• Evaluate research into anxiety as a factor affecting EWT: affected be individual differences.

  This is because research has found that those who score low on neuroticism (who do not tend to get anxious as easily) produce better eyewitness testimonies when anxiety levels rise. In contrast, those who score high on neuroticism (tend to get anxious easily) produce poorer eyewitness testimonies when anxiety levels rise. This is a limitation because it suggests that it is difficult to generalise the effects of anxiety on the accuracy of EWT as it depends on personality traits.
• Evaluate research into anxiety as a factor affecting EWT: ethical implications.

  For example, the research finding that witnesses who experience a high level of anxiety produce less accurate testimonies may result in the public, jury members and judges disregarding testimonies from witnesses/victims to serious crimes. This is a limitation because it may lead to further distress to victims who feel that their voices are not being heard and may result in the offender escaping criminal justice due to a lack of evidence.