Usefulness of a research refers to how well a study has been carried out and can therefore expand scientific knowledge as well as apply to the wider population. In this case, research into persuading a jury is able to provide us with explanations as to how or why jurors sometimes react in a certain way when presented with different scenarios in the trials.
A strength of this type of research is that it presents useful evidence which aids the government with ideas as to how to manipulate the trials so that both sides get a fair trial. For example in the study of Loftus into expert testimony it was found that if it was used in a trial, it was likely to arise more doubts about the defendant’s guilt for the jurors, so Loftus stated that if both sides use an expert it may lead to a battle of experts and as a result jurors may be confounded even more. It can therefore be seen how expert testimony should not be used often and by both sides, something which potentially trials can put into practice. Another strength of this type of research is that it’s generally quite cheap to carry out, as it usually uses self-reports to obtain results, so many can be carried out and thus vast amounts of data can be collected. This means we can apply these results to the area that we are investigating, in this case persuading a jury.
On the other hand, all of the research that has been carried out into persuading a jury has been based on mock trials. For example in the Pennington & Hastie study 130 students listened to tape recordings of a mock trial, and although mock trials may resemble real trials, they are not the real thing which means the methodology lacks ecological validity as the settings are usually lab experiments, making the results less valid and thus less useful. Also, most of the research into persuading a jury uses students as participants who were paid to participate or volunteered, such as in the study of Pickel et al. This means the participants may have suffered from demand characteristics as the students may have reacted according to what they thought the experimenter wanted, and since most participants were psychology students participating for extra credits this results in the findings being biased and thus unreliable.
Overall, research into persuading a jury is useful as it allows for criminal psychological knowledge to be expanded, as the study of Loftus shows, yet its usefulness is challenged by the fact that most research involves using mock trials which lack mundane realism and are unrepresentative of real trials. However, if it was done otherwise, ethical issues may arise, since a defendant is innocent until proven guilty, which still makes this type of research very useful.