Role of Jury Instructions in Criminal Trials

摘要

The role of jury instructions in criminal trials was studied. Procedures were developed for assessing and rewriting jury instructions for effectiveness on three different levels. The procedures resulted in significant improvements in jurors' comprehension after each successive rewriting effort for both the complex and simple instructions. Regarding achieving sufficient comprehensibility, the definition of what is or is not sufficiently comprehensible will depend on the judgments of the legal community ultimately. Results suggest that with more rewriting effort expended, even the more difficult items could reach standards of sufficiency. As to achieving real life validity, testing showed the rewritten set of instructions resulted in questions being answered correctly 78% of the time on the average. It is suggested that the trial and deliberative processes may have some corrective effect on poorly drafted instructions, but not enough to raise the instructions to an acceptable level of comprehensibility. The methodological developments within this project are significant in that now a scientifically sound and easy-to-follow method is available for use in producing maximally comprehensible jury instructions.