The mean number estimated by participants asked earlier about the group of 4 demonstrators was significantly lower than those asked about the group of 12, supporting the claim that post-event information can negatively influence memory recall accuracy.
After a week delay, further questions were posed to participants, including one asking how many demonstrators were in the video.
One factor that could negatively influence EWT accuracy is misleading information - i. Evaluation of EWT misleading information research Strengths: - There is a large base of evidence suggesting that misleading information can lead to EWT inaccuracy, which has raised awareness that the criminal justice system cannot always rely on EWT as a basis for [sometimes incorrect] convictions.
This can, therefore, result in unreliable eyewitness testimony. Many people believe that memory works something like a videotape. However, participants in the co-witness group were told that they had watched the same video; however, they had in fact seen different perspectives.
Weaknesses: - Laboratory experiments may have low external validity i. The distortion could be the result of poor memory, where people assimilate new information into their own accounts of the event and are unable to distinguish between what they have seen and what they have heard.
However, a study by Yuille and Cutshall contradicts the importance of stress in influencing eyewitness memory. It is reasonable to argue that the students in their experiment were less experienced drivers, who may be less accurate at estimating speeds.