Pendrod & Cutler (1989)

• • The sample consisted of undergraduate psychology students as mock jurors and experienced jurors.  
  • -The psychology students may have shown demand characteristics as their undergraduate course result was affected by their participation in the study.  
• • The participants watched a video recording of a trial.  

  -The task of watching a video lacks internal validity as this is not how a jury would normally make a decision in a trial. 
• • The jurors were either shown or not shown expert testimony clips in the video.  

  -Ecological validity is limited as in every day trials jurors would always see any expert testimony before making a decision. 
• • The participants rated the credibility of the eye witnesses.

  -The race of the jurors may affect their ratings of credibility of the eye witness, as shown in Bradbury (2013), reducing reliability of the data gathered.
• • Evidence in trials presented by experts could bias the jurors towards the individual testimonies of those in high regard, like police officers.
  • +Penrod and Cutler (1989) found jurors are influenced by the confidence/expertise of the eyewitnesses so their decisions are not objective.
• • The race of the jurors may affect their perceptions of the defendants with jurors who are a different race to the defendant being more likely to convict them. 

  +Bradbury and Williams (2013) found juries with a high percentage of white jurors were more likely to convict black defendants so decisions are not objective.
• • Pre-trial publicity in the media about the defendant/crime/victim before the trial can influence jury decisions during the case. 
  • +Ruva, McEvoy and Bryant (2007) found that negative pre-trial publicity had a biasing effect on juror impressions of the defendant.
• •  Investigating jury decision-making is often done through mock jury trials which replicate a court trial.
  • -A mock jury trials use video recorded trials so may not reflect real life trials as it lacks ecological validity, so jurors may be more objective where there are higher stakes and real people involved.