The authors look at why jurors who hear the same evidence and arguments in the courtroom later disagree about the proper verdict, how biases and prejudices affect juror decisionmaking, and the extent of juror rationality. Major theories of juror decisionmaking are reviewed, along with research that has been conducted to evaluate their validity. Juror decisionmaking models are detailed that focus on the link between attitudes and verdicts, the influence of outcome information and attitudes on juror decisionmaking in search and seizure cases, algebraic models of juror decision processes, formal and empirical research on cascaded inference in jurisprudence, and argument structuring and evidence evaluation. Commentaries are included that address juror decisionmaking and the need for jury research. References, tables, and figures