The ability of jurors to deal with the complex issues involved in contemporary civil litigation has been of increasing concern. There is currently no formally accepted definition of complex litigation nor has there been an empirical demonstration of the dimensions of complexity. Further, little is known about how complexity may interfere with jurors' ability to reach a verdict. This study examines effects of evidentiary and legal complexity on the jury decision process. Integrating and adapting recently developed theoretical approaches to jury decisionmaking, the research aims to test an explanation-based model of decisionmaking that suggests that jurors process evidence as a narrative organization of the trial data in which causal and intentional relations are of fundamental importance. Decisionmakers are presumed to construct an intermediate memory model of the trial data, and this representation, not the "raw" evidence, guides interpretation of the evidence. An experiment will be conducted to test this story model using 864 jury eligible individuals. The design includes the investigation of the influence of three dimensions of evidence complexity: informational load (high, moderate, or low rate of processing); technical complexity (high and moderate); and implicational clarity (pro plaintiff, pro defendant, and neutral or ambivalent). This research promises to make a major advance in jury research. Introducing trial complexity into this line of research will have significant theoretical and practical implications for understanding juror decisionmaking. The analysis will also make an important contribution to cognitive psychology by contributing to our understanding of cognitive strategies for coping with complex judgment tasks.
