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Current Issue : Winter 2007-2008

Edward Cheng

"My work attempts to combine science and law, the two things I love," says Professor Edward Cheng. In bringing a scientist's mind to the study of law, Cheng is developing an expertise in a new area where evidence, torts and criminal law intersect. With a background that includes degrees in electrical engineering and information systems as well as a J.D. from Harvard Law School, he is bridging the often troubling gap between law and science that judges, juries, experts and lawyers increasingly face.

After shying away from the lab work aspect of his science studies, Cheng found himself attracted to the broader applications of the law. "Law allows you to constantly look for links," he relates. "Going to law school made me see scientific concepts differently." His scholarship focuses on how scientific evidence is used in the courtroom. As a scientist, he is comfortable with the trend in legal scholarship toward empirical studies, but he always makes the numbers relevant. "I try to target my empirical work toward issues that judges care about," he explains. "A number of my pieces address how judges think and behave."

His most recent work (see abstract) challenges the myth that federal judges are, and should be, generalists who can adeptly deal with a variety of matters. "Conventional thinking is opposed to specialized courts. The argument is that they will result in disjunctions among areas of the law, or that specialized judges will develop the law in arcane, esoteric ways that attorneys, not to mention their clients, won't be able to understand," he says. Cheng challenges that notion by showing that first, federal judges are specializing; it happens when the appellate courts decide which judge will write an opinion, for instance. He then argues that this type of specialization is actually a desirable outcome.

In another work in progress, Cheng is addressing a controversy that the legal profession is just now beginning to acknowledge — the tension between clinical and statistical decision-making. "We generally don't like statistical decisions in law," he says. "We don't want to put people in jail based on probabilities." However, the clinical-based approach, in which people make judgments using their experience and intuition, can result in higher error rates because of bias, inconsistency, and the way people imperfectly process information. "Whether we like it or not, the field of law is being dragged into this debate because of the increasing prevalence of statistical evidence," Cheng says. "Judges deal with this all the time. We can't ignore it."

In his draft article, he identifies different areas of the law where the tension between clinical and statistical approaches arises. For example, can a plaintiff allegedly harmed by a chemical rely solely on his doctors' clinical judgments, or must he provide epidemiological studies? In a discrimination case, should a claimant be allowed to rest her claim purely on statistical evidence, or should the law require evidence that discrimination tainted her particular case? "Rarely if ever," writes Cheng, "has the legal community recognized that all of these seemingly disparate issues fundamentally raise the same question." He hopes this new article will help judges and practitioners to recognize the problem and encourage the development of greater coherency between the approaches.

Cheng regularly brings these issues into his seminars, where students learn to think critically about statistics and other forms of evidence. An evidence colloquium he taught last year featured a variety of outside speakers whose ideas and working papers were challenged by students in biweekly colloquia. "Our students are not easily cowed," reports Cheng. "They really seemed to relish the opportunity to engage the speakers."

Edward Cheng | Abstract

The Myth of the Generalist Judge: An Empirical Study of Opinion Specialization in the Federal Courts of Appeals

Despite the frequent rhetoric celebrating the generalist judge, do judges really believe in the generalist ideal? This article empirically tests this question by examining opinion assignments in the federal courts of appeals from 1995–2005. It reveals that opinion specialization is a regular part of circuit court practice, and that a significant number of judges indeed specialize in specific subject areas. The article then assesses the desirability of opinion specialization. Far from being a mere loophole, opinion specialization turns out to be an important development in judicial practice that promises to increase judicial expertise without incurring many of the costs commonly associated with specialized courts.



COURSES Criminal Law, Evidence, Torts, Seminars: Scientific Evidence, Statistical Inference and the Law

  • Modern Scientific Evidence: The Law And Science of Expert Testimony(Thomson West 2007-08 ed.) (with David Faigman et al.)
  • Independent Judicial Research in the Daubert Age, 56 Duke L.J. 1263 (2007)
  • The Perils of Evidentiary Manipulation, 93 Va. L. Rev. In Brief 191 (2007) (response)
"I try to target my empirical work toward issues that judges care about."