Loftus and Palmer (1974) Studied eyewitness testimony
Method, Results, Conclusion and Evaluation.
Experiment 1: Method: were shown a film of a multiple car crash. They were asked a series of questions including "How fast do you think the cars were going when they hit?" In different conditions the word hit was replaced with "Smashed", "Bumped" or "Contacted".
Results: Participants given the word "Smashed" estimated a higher speed, and the word "Contacted" estimated a lower speed.
Experiment 2, Method: 3 groups, Group one given the verb smashed, second was given the word hit and third didnt get any word. 1 week later they were asked did you see any broken glass?
Results: Participants were more likely to say there was broken glass with the word smashed even though there wasnt any.
Conclusion: Leading questions can affect the accuracy of people's memories of an event.
Evaluation: (-) articifal experiment as they were watching a video. (-) Demand characteristics.
The Age of the witness can affect the Accuracy of
Valentine and Coxon (1997) Studied the effect of age on EWT.
Method, Results, Conclusions, Evaluation
Method: 3 groups of participants (Children, young adults and elderly people) watched a video of a kidnapping. They were asked a series of leading questions about what they had seen.
Results: Both elderly and children gave more incorrect answers to non leading questions. Children were misled more by leading questions.
Conclusion: Age has an effect on the accuracy of EWT.
Evaluation: (-) Experiment was artificial and wasn't as emotionally arosing as it would be in real life. (-) Lacks ecological validity.
Anxiety can affect focus
Loftus (1979) Studied weapon focus in EWT
Method, Results, Conclusion, Evaluation.
Method: Independent groups design. participants heard a discussion in a nearby room. In one condition the man came out of the room with a pen and grease on his hands. In the other he came out with a knife and blood on his hands. Participants were asked to identify the man out of 50 photos.
Results: Participants in one condition were 49% accurate. Only 33% were correct in condition two.
Conclusion: when anxious and aroused, witnesses focus on a weapon at the expense of other details.
Evaluation: (+) Hight ecological validity (-) Ethical issues, participants could have been very stressed at the sight of the man with the knife.
The Cognitive Interview was developed to increase
The Cognitive Interview
1) Interviewer trys to make the witness relaxed and tailors his/her language to suit witness.
2) The witness recreates the enviromental and internal mood of the crime scene
3) The witness reports everything they can remember about the crime.
4) The witness is asked to recall details of the crime in different orders.
5) The witness is asked to recall details of the crime from various different perspectives.
6) The interviewer avoids any judgemental and personal comments.
Research to support the Cognitive interview.
Geiselman et al (1986) Studied the effect of the cognitive interview
Method, Results, Conclusion, Evaluation
Method: In a staged situation, and intruder carrying a Blue rucksack entered a class room and stole a slide projector. 2 days later, participants were questioned about the event. Independent groups design - either questioned with a standard interview or the cognitive interview. They were asked "was the guy with the green backpack nervous?" and later asked what colour the man's rucksack was.
Results: Participants in the Cognitive interview were less likely to recall the rucksack as being green.
Conclusion: The cognitive interview technique enhances memory recall and reduces the effect of leading questions.
Evaluation: (+) High ecological validity (-) Independent groups design, participants in the cognitive interview could have been naturally less susceptible to leading questions that the other group.