Hastie et al discovered that the final verdict of juries was reflected the views of the majority of jurors prior to the deliberation (86% if final decision was innocent and 90% if guilty.) Due to the fact that this study was carried out on an actual trial, the ecological validity is greatly improved. However, we do not know which cases were involved within the study, which means that we are unaware of the nature of these cases. One could also inquire as to whether the jury was presented with quantitative or qualitative data. This would affect the likelihood of compliance because the more ambiguous the information, the more certain they will be about their decision. Kaplan and Miller

Moscovici's blue-green slide experiment triggered a flurry of research into the factors that lead a minority to exert influence over a majority. 172 participants were used in total, however only 6 were used at one time; one problem with this is that a jury is made up of 12 participants, so therefore psychologists have to be careful when generalising the findings as they may be unrepresentitive. This study was a standardised procedure, this would have increased relaiblity, however on the other hand participants may have realised this and as a result may be prone to demomstrate demand characteristics as they know they are in an experiment. Another weakness with this study is that it can be argued that it is un-ambigious as there is a common misconception over blue and green as different shades can appear blue to one person and green to another, therefore results aren't completely valid. Although there were significant findings from this study; numbers were low, this suggests that minority influence doesn't always have a massive impact on others. This study isn't very representitive of Juries as deciding whether a slide is blue or green is completely different to deciding whether someone is guilty or not.

Another study on minority influnce is the work of Nemeth and Wachtler, they conducted a mock trial on a compensation case. One problem with mock juries is that there is a lack of ecological validity; meaning it is a unrealistic environment and ignores the complexity of the case. Participants might not take a mock trial as seriously as they know their final decision will have no life changing impact on the 'criminal'. In the study the "jury" were asked to decide on the amount of compensation that the defendant should receive, in a real case the jury doesnt decide any sentencing, they only decide on whether the defendant is guilty or innocent. Another weakness is that research into minority influence should be on one single participant changing the majority vote of either guilty or innocent to the other one, however this study had the mock jury deciding on the amount of money which should be given as compensation; this is less likely to test minority influence as there is a wider range of answers and the agreed answer may be influenced by social norm which is when participants meet in the middle and go with the most common answer. All the participants were adult students, this is a problem as it is not representitive of a jury as juries have a wide range of participants from all backgrounds. The mock jury was made up on groups of 5, this is also unrepresentitive as real juries consist of 12 participants 

- Hastie conducted a study a study using 69 mock juries requring a 12 to 0, a 10 to 2 or 8 to 4 verdict. Compared to the juries needing a unanimous verdict, those requirng a majority one spent less time discussing and more time voting . He also suggested also showed that when need a unanimous verdict jurors often bullied others to agree with them!

Evaluation - used a mock jury  to conduct experiments so not always helpful or representitive of the real world as the judgement would have no real consequences for a real person.

Defendant’s ethnicity;

·Steriotypes based on ethnicity effect jurors’
decisions

·Duncan varied the ethnic group of the
perpertrator and victim in a video tape of a potentially violent situation. Results
showed that participants judged an ambiguous shove as more violent if performed
by a black person than a white person 

Results;

Tape1-white defendant, white victim

Tape 2-white defendant, black victim

Tape 3- black defendant, white victim

Tape 4-black defendant, black victim

When the perpetrator was black 70% of participants described
it as violentand white was only 13 %. And attribution of violence was highest
for tape 3 and lowest for tape 1.

.In a mock jury situation pfeifer and ogloff
found that white participants were more likely to judge a black then a white defendant
guilty in a rape case, especially when the victim was white. When asked to
justify the guilty verdict the reasoning was down to the ethnicity of the
person rather than actual evidence. This shows it is due to stereotyping

·Judgments of ethnic minorities are similarly
biased in real trials, Baldwin and McConville found that black defendants’ were
more likely to be wrongly convicted  and
wrongly acquitted and this was the case even if the members of the jury were
black