This issue has been considered in discussions of the relative merits of the adversarial and inquisitorial systems of justice. Experimental studies focusing on this issue have been conducted in the United States and Germany. They have used simulations to determine how incriminating statements by witnesses are evaluated if later cross-examination reveals the statement to be wrong or useless and how previous knowledge of investigative records influences the decisions made during the trial. The results have generally suggested that the active conduct of a trial by a judge who has no previous knowledge of a case offers the best solution to the task of processing information in an objective and neutral way. Such a mixed form of trial does not correspond to either the current German system or the American system, however. Figure and 29 references.