• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Measurements of Accuracy of Eyewitness Testimonies

Extracts from this document...


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.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Cognitive Psychology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

4 star(s)


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

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Cognitive Psychology essays

  1. Marked by a teacher

    In this essay I am going to contrast and compare three approaches in psychology ...

    4 star(s)

    The focus of the cognitive psychologists is on the way the brain processes information (stimuli) received (input) which leads to a certain behaviour (output). This process is compared with the computer function. This comparison is not too coherent because the human mind/the brain, is far more advanced than a computer.

  2. Critically assess Piaget's theory of cognitive development

    To illustrate this, Francoise Frank, reported by Bruner (1964), showed that pre-operational children were much better at liquid conservation tasks if they were encouraged to use their verbal skills. Frank screened much of the beakers used so the children would not rely so much on visual skills, instead having to

  1. Recall in Memory Using Mnemonics

    Target Population: School students aged 15-18 The sample population chosen was na�ve to the true nature of the experiment and had no Psychology background, as this would affect their responses to the tasks. The Participants were allocated top their groups by choosing number cards (1=control, 2=experimental).

  2. 'Organisation in Memory'.

    Therefore, I was able to conclude that my experimental hypothesis, organisation of words increases recall, is a true statement. Introduction When investigating memory in psychology, organisation is a key factor to consider. Without organisation of a memory, the speed at which information is recalled or accessed from the memory would be considerably slower.

  1. Memory is an important area of study in Psychology because it underpins our other ...

    couldn't recall them as grouped categories. Cheating wasn't an extraneous variable as it was made sure that the subjects were all spaced evenly so that they couldn't see each other's answers.

  2. AS Psychology Essay &amp;amp;#150; Memory &amp;amp;#150; Forgetting

    As we learn, decay theory presumes that a structural change to the brain takes place (the engram). So according to decay theory metabolic processes occur over time, which break down and degrade the engram, unless it's maintained via repetition and rehearsal.

  1. Categorisation in Long-Term Memory

    Hypothesis My study will show the differences in the accuracy of recall between words which are categorised and words which are listed randomly. Words which are in some kind of order will improve the semantic coding and therefore more of the words will be recalled then with a random list of words.

  2. This study is based on the theory of cue dependent forgetting - more specifically, ...

    all situational extraneous variables could be controlled and it would be possible to replicate it exactly. Additionally the same two locations could be used but learning could take place in the dining hall to test whether an association of a classroom with learning affects recall.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work