For decades, psychologists have been concerned about improving juror processing of evidence. Several procedural innovations have been suggested, including permitting jurors to take notes, ask questions and discuss the trial before deliberations. Another tool that courts have considered is providing jurors with summary information about the evidence presented in court. These evidence summaries can be presented at trial in statements by the judge, attorneys and special summary witnesses. Statements made by the judge are sometimes permitted to summarize the evidence as long as they do not provide an opinion about it. Attorneys are permitted to make "interim commentary" in some cases, which are similar to opening statements or an additional but earlier closing argument. In complex cases, attorneys can call on summary witnesses to summarize evidence presented by other trial witnesses. These summaries are used infrequently and are typically limited to very complex cases.

But is it permissible?

A case recently docketed by the Supreme Court raises issues about the propriety of summary information. In Harms v. United States (Docket number 06-990, ruling below at 442 F.3d 367, 5th Cir.), the prosecution called a summary witness with a flow-chart presentation during a workers' compensation trial. The appellate court reasoned that the case was complex enough to warrant a summary witness. The summary witness's admission was upheld because his testimony was consistent with the evidence presented at trial and because it did not provide argument or advocacy.

The fact that a limiting instruction was given to the jury about how they should use the summary witness and that the flow chart was not available during deliberations was critical to the appellate court's decision to uphold the admission of this evidence. The specific question the Supreme Court is now being asked to address is whether the presentation of this nonexpert summary witness and accompanying flow chart was permissible. However, the case raises several psychological questions about the potential for summary information to improve trial processes. Among them is whether presenting any form of summary information helps or inhibits jurors' processing of the evidence presented at trial. If it can be harmful to processing, there are additional questions raised about procedural steps that can be taken to minimize or eliminate any negative effects.

What the research says

Psychological research indicates that summarizing information can help people learn that information. Highlighting the important facts in a summary generally helps people learn new information, and it can increase their comfort with the material. In fact, summarizing the information might result in better decision-making.

In addition, psychological research on information processing indicates that when people are confronted with complex information, they may rely upon heuristics in their decision-making. Summarizing the information may make the decision cognitively manageable and correct for bias resulting from cognitive shortcuts.

Although these theories shed light on the possible effects of summary information at trial, research on this specific topic would better inform decisions such as those presently before the Supreme Court. The small existing body of research on this topic indicates thatsummary information and flow charts are likely to have a positive impact on jurors, meaning it could help them make better decisions. For example, research on the use of flow charts indicates they can increase comprehension of jury instructions, and this positive effect may be increased even further if jurors are permitted to use the charts during deliberation. Summaries have shown similar potential to increase comprehension of expert testimony. A summary of the likely content of the expert's testimony may help jurors organize and understand the information. Judicial summaries, although not the subject of this case, may also increase jurors' ability to recall relevant evidence. Summaries and flow charts might be helpful because they may reduce the cognitive burden on jurors and allow them to process the trial evidence more effectively.

Research on the effects of summary information could assist trial judges in making decisions about allowing summaries at trial, and it could aid the Supreme Court in making policy about the use of summary information. So far, research indicates that summary information may help jurors perform their duty. However, more psychological research targeting the effect of various types of summary information, similar aids to jury processing, and on appropriate safeguards to protect trial fairness during their use would further inform these types of decisions.

"Judicial Notebook" is a project of APA's Div. 9 (Society for the Psychological Study of Social Issues).