Because one of the most visible dispensaries of justice is the trial, it has become a central focus of much of the recent psycholegal research efforts. In a series of studies, Thibaut and Walker demonstrated that the type of system (adversarial or inquistorial) makes a major difference in the psychological atmosphere it creates in the courtroom. The adversary system is more apt to instill in its participants a satisfied feeling that fairness has been achieved. Another hallmark of American justice is the jury trial. In a 1966 study, Kalven and Zeisel found that out of their sample of 3,576 criminal cases, judge and jury would have agreed 78 percent of the time. This high level of agreement has led one legal commentator to speculate that judges may unconsciously communicate their preferences through nonverbal cues to the jury. Numerous studies have concentrated on the relationship between the juror's personality and its effect on the interpretation of evidence. The McGlynn, Megas, and Benson study found that females are more likely to be found not guilty by reason of insanity than are males. Although the judge is equally if not more important than the jury in the trial process, relatively little experimental attention has been paid to his or her work. Of all the areas of psycholegal research, the area of psycholegal research, the area of witness testimony has the oldest tradition. Such aspects as perception and memory, external factors, and articulation of answers have been considered in research efforts. If psycholegal research is to improve and become more useful, certain key issues must be addressed to a greater extent than in the past. Future research must be applicable to relevant questions, be externally valid, and yield conclusions which can be generalized. Approximately 300 references are included.