PED | factors affecting the accuracy of EWT

Question 1

Gabbert, 2003

Answer 1

Laboratory experiment

Independent groups

Volunteer sampling

Question 2

Procedure

Answer 2

60 students from Aberdeen university and 60 older adults were shown a video of a girl stealing money from a wallet

Participants watched the video in pairs and were told they had watched the same video, when in fact they had watched the scene from different perspectives. In only one of these would the participants have seen the girl steal the wallet

Participants were free to discuss what they had seem before individually completing
a test of recall

Question 3

Findings and conclusions

Answer 3

71% who watched the video in pairs recalled information they had not actually seen, with 60% saying the girl was guilty despite not having seen her commit the crime

In a control group where there was no discussion, no errors were made

This shows that, when witnesses discuss their memories of an event, they can contaminate the memories of others making them think they have witnessed something they have not

Gabbert et al concluded that witnesses go along with each other either to win social approval or because they believe that other witnesses are correct and they are wrong. They called this memory conformity.

Question 4

Bodner

Answer 4

2009 explained how the effects of post-event discussion can be reduced when witnesses are warned about source monitoring and conformity

Found that participants recall of an event was more accurate when they were warned not to recall anything they had not seen for themselves

This shows that testimony is more reliable when witnesses are aware that their recall could be affected by discussing it with others or if they felt the pressure to conform with what others said they had experienced

Question 5

Eval 1

Answer 5

Limitation of this study is that is has low population study which is when the findings cannot be generalised to wider populations, lowering the external validity of the research

This is because there were only 120 participants in the study from one area in Scotland asked about one artificial crime

As such the results of this study may not be generalisable to other people or to other events

Meaning it may not tell us much about post-event discussion in wider settings, for example more serious crimes

Question 6

Evaluation 2

Answer 6

A strength of this study is that it has high levels of control over extraneous variables

Which are variables that could have an undesirable effect on the results if they are not properly controlled affecting the internal validity of the results

As the experiments were laboratory experiments, extraneous variables, such as the length of time participants watched the video for can be controlled

This means we can be certain the misleading information led to the difference in judgements and not other factors