Misleading information - accuracy of EWT

• Eyewitness Testimony: The evidence provided in court by a person who witnessed a crime, with a view to identifying the perpetrator of the crime.
• Leading questions: A question that is phrased in a way that encourages a certain answer, usually a desired answer.
• misleading information: the supplying of information that alters an individual’s memory of a past event.
• post-event discussion: when participants discuss the event afterwards, their own memory of the event may become contaminated.
• stages of eyewitness memory: encoding of information into LTM, retains info for a period of time which can be lost or modified, retrieval of info from LTM - memory may be inaccurate.
• Witness factors: age, race, gender, response to anxiety or stress.
• Event factors: The factors that cause the event to occur, such as the weather, the time of day, the location or the level of violence.
• information received after an event can have a retroactive effect on memory.
• Loftus and Palmer’s study aimed to investigate the effect of leading questions and misinformation upon estimates of speed.
• experiment 1 procedure (Loftus): lab study, independent measures design. 45 students placed in different groups each watched 7 films of a traffic accident. after watching each film, they were asked to fill out a questionnaire about what they had seen, and specific questions about the film. they were then asked a critical question about speed of the cars.
• what was the independent variable in Loftus’ study?

  the verb used in the critical question - ‘hit‘ or ‘smashed’
• loftus found that people who answered the 'smashed' question gave a mean estimate of 39 mph whereas those who answered the 'hit' question gave a mean estimate of 28 mph.
• What was the dependent variable in Loftus’ study?

  the mean speed estimate given by the ppts in m/s.
• experiment 2 procedure (Loftus): Lab experiment, independent measures. 150 ppts were divided into three groups and shown a car accident that lasted 4 seconds out of the 1 minute video. one group was asked critical questions with the verb ‘hit’, one with ‘smashed‘ and one with no question asked at all. They were then asked if they saw any broken glass after a week.
• results of experiment 2: ppts were more likely to answer ‘yes’ to there being broken glass if they were asked the critical question with ‘smashed’. 16 smashed, 7 hit.
• what was the independent variable in Loftus’ study (2)?

  Type of verb used in the question, or if there was no question asked.
• what was the dependent variable in Loftus’ study (2)?

  whether the ppts answered yes or no to the question about broken glass.
• strength of the effect of misleading information: there is research support for the effect of misleading information on EWT. Loftus‘ study with misleading info about bugs bunny - many falsely recalled that they remembered seeing bugs bunny at Disney as a child whereas he was never a Disney character. this shows how misleading information has a powerful effect in creating a false memory.
• limitations of the EWT: there is research criticism for lack of ecological validity and inaccuracy affecting reliability. lab experiments for Loftus’ study do not reflect real aspects of everyday life and lack mundane realism. Eg, Foster found that higher anxiety situations affected recall capability (witnessing a real robbery). Thus misleading information may not have such a powerful effect in real life.
• Gabbert post-event discussion procedure: ppts placed in pairs were each shown a video of the same event, a girl stealing money from a wallet, at a different perspective. they were then allowed to discuss what they had seen and asked to answer questions on a questionnaire.
• Gabbert post-event discussion result: 72% of ppts recalled information that was not shown in their video after speaking with their partner. thus memory can be contaminated through discussing events.