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Measurements of Accuracy of Eyewitness Testimonies

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Measurements of Accuracy of Eyewitness Testimonies Abstract This study was designed using an account of a car accident. The aim was to measure the affect of re-wording a single sentence, on the estimation of how much alcohol was in the bloodstream of the driver. 20 undergraduate participants (10 male and 10 female) all with clean licences were used. They were randomly given a vignette describing the car accident, where half the subjects read that the driver 'smashed into' a garden wall, and the other half read that the driver 'bumped into' the garden wall. Participants were required to read the vignette and then estimate how much over the British legal alcohol limit the driver was, for example, 200% indicates that the driver was twice the limit, 110% would mean he was 10% over and 50% would mean he was half the limit. The hypothesis predicts that those who received the vignette stating the driver 'smashed into' the wall are more likely to estimate a higher limit, than those who read that the driver had 'bumped into' the wall. The results of this investigation show that the mean estimation for those in the 'smashed into' condition (143%), was significantly greater than those in the 'bumped into' condition (108%), where p<0.05. This means that the experimental hypothesis was accepted, and the null hypothesis was rejected. ...read more.


In actual fact, there was no broken glass in the film. Loftus and Palmer suggested that two kinds of information go into a person's memory of a complex event; information obtained from perceiving the event, and information supplied after the event. This study aims to see if the above effects can also occur when subjects simply read about an event, rather than actually see it, i.e. can their response to the event still be biased? Subjects will be presented with a vignette in which a character (John) drove his car after drinking and either 'smashed into' or 'bumped into' a garden wall. Subjects will be required to estimate John's blood alcohol content relative to the British legal limit. Based on the evidence given above: The Experimental hypothesis for this investigation is, "The estimate for Driver's blood alcohol levels will be higher when the word 'smashed' is used than when the word 'bumped' is used." The Null hypothesis for this investigation is "The estimate for the driver's blood alcohol levels will not be higher when the word 'smashed' is used than when the word 'bumped' is used." Method Subjects: 20 undergraduate drivers (10 male and 10 female) all with clean driving licences. Materials: A vignette in which a character named John left his friends' house at 2:20am. ...read more.


Another limitation was gender bias. The driver in the vignette was male which could have meant that male participants may have been more sympathetic to him when giving an estimation. If a female character had been used, the results may have been different. This could be improved by using two sample groups, both with female characters, but again with either the 'smashed into' condition or 'bumped into' condition. The results of this and previous studies have a number of implications in today's society. Loftus and Palmer's work (1974), showed how changing a verb in a sentence, can alter eyewitness recall of a car accident. These findings have major implications for the Legal Justice Systems. In a study by Rattner (1988), a review of 205 cases of wrongful arrest showed that 52% of the cases were associated with mistaken eyewitness testimonies. These results highlighted the unreliability of eyewitness testimony. Other studies have demonstrated that witnesses sometimes cannot attribute memory to its appropriate sources, or that they make source attribution errors. When witnesses get information from other witnesses and from the police, then their own recollection is likely to be contaminated (Fisher, 1995). This is yet further evidence suggesting that there should be less dependence on eyewitness testimony, and with the arrival of advanced gene technology, it is now possible to use alternative sources of evidence. ...read more.

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This is a good piece of work that covers the topic of measuring eye witness testimony. The writer has referred to some of the major studies that have been carried out although it is uncertain who carried out the main study which the writer refers to at the beginning. In parts the writer needs to simplify the language and use their own words to improve the score.



Marked by teacher Linda Penn 07/08/2013

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