Testimony

Acquisition is the shaping of memory and the perception invloved.
Perception is subjective, it relies on selecxtive enterpretation.

when people give out an account in court of what they have seen, they are witnessed to say the 'whole truth' ; this truth can only reflect their account of what they actually noticed when the crime was committed.
AINSWORTH (2000)

Duncan (1976) carried out a study in which he examined the effect of ethnicity had on peoples perception of a particular event.
Particpants watched a short film of two people pushing each other.
in one condition the 'pusher' was white, in the second the 'pusher' was black.
all the participants were white college students (USA). they were then asked to write down what they saw, and whether the 'pusher' was being violent or playing around.

he found when the 'pusher' was white 68% said he was playing around. whereas in the black condition 70% said he was being violent

Malpass and devine: Show how the retention of information can be affected quite considerably by the length of time between the event and the giving of evidence.

malpass and devine compared the accuracy of identification of a suspect in witness who were asked for evidence immediatly after an event, and those who witnessed an event after 5 months.

in the 3 day condition. 83% were accurate

in the 5 month condition only 36% were correct

Loftus - Eye witness Testimony

1974- loftus' study on leading questions, and the effect of eye witness testimony. AS

LOftus also carried out a study of eye-witness tesimony in court. she asked participants, acting as if they were jurors to read an account of burglary and murder. 1 condition= no eyewitness. 2nd condition =credible eye witness, 3rd condition = eyesight of witness questioned.

• Results:
  
  

  1 condition. 18% thought defendant guilty
  2 condition. 72% thought guilty
  3 condition. 68% guilty.
  

• both studies lack ecological validity as they were shown clips instead of real events, the latter as the particpant knew they were not really convicting an offender

Estimator variables

Weapon focus effect- one variable which can influence accurate identification of a suspect

LOFTUS:
participants shown two different films, one a man holding a gun, the second a man holding a cheque.
She found that the cheque condition was more accurate in terms of identifying the culprit from a line-up.
Lftus concluded this was the effect of weapon focus.

AINSWORTH
if a witness of victim is particularly distressed they may find it difficult to take in information at the time of the event. and perhaps it more difficult to recall testimony in court. for most witnesses in court is stressful. (2002)

System variables:

much of this research focuses on courtroom practices, and questioning techniques used by the police and the judicary use with witnesses.

the wording of questions can sometimes be used to influence the witness.- (loftus and palmer)

closed questions

open questions

negative questions

double negative questions

multi-part

Leading questions

Cognitive interview technique

Four stages:
recreating the context
focused concentration
multiple retieval attempts
Varied retieval

Effectiveness. most studies support this and feel witnesses remember more whilst using this technique.

ETHICS: many police officer are reluctant to use it

as they believe it may traumatise the victime further.