Evidence Commons^™

Embracing Deference, Edward K. Cheng, Elodie O. Currier, Payton B. Hampton

Vanderbilt Law School Faculty Publications

A fundamental conceptual problem has long dogged discussions about scientific and other expert evidence in the courtroom. In American law, the problem was most famously posed by Judge Learned Hand, who asked: "[H]ow can the jury judge between two statements each founded upon an experience confessedly foreign in kind to their own? It is just because they are incompetent for such a task that the expert is necessary at all." This puzzle, sometimes known as the "expert paradox," is quite general. It applies not only to the jury as factfinder, but also to the judge as gate- keeper under the …

The Consensus Rule: A New Approach To Scientific Evidence, Edward K. Cheng

Vanderbilt Law School Faculty Publications

Founded on good intentions but unrealistic expectations, the dominant Daubert framework for handling expert and scientific evidence should be scrapped. Daubert asks judges and jurors to make substantively expert determinations, a task they are epistemically incompetent to perform as laypersons. As an alternative, this Article proposes a new framework for handling expert evidence. It draws from the social and philosophical literature on expertise and begins with a basic question: How can laypersons make intelligent decisions about expert topics? From there, it builds its evidentiary approach, which ultimately results in an inference rule focused on expert communities. Specifically, when dealing with …

The Science Of Gatekeeping: Using The Structure Of Scientific Inference To Draw The Line Between Admissibility And Weight In Expert Testimony, Christopher Slobogin, David Faigman, John Monahan

Vanderbilt Law School Faculty Publications

Fundamental to all evidence rules is the division of responsibility between the judge, who determines the admissibility of evidence, and the jury, which gauges its weight. In most evidentiary contexts, such as those involving hearsay and character, threshold admissibility obligations are clear and relatively uncontroversial. The same is not true for scientific evidence. The complex nature of scientific inference, and in particular the challenges of reasoning from group data to individual cases, has bedeviled courts. As a result, courts vary considerably on how they define the judge's gatekeeping task under Federal Rule of Evidence 702 and its state equivalents.

This …

Being Pragmatic About Forensic Linguistics, Edward K. Cheng

Vanderbilt Law School Faculty Publications

This article aims to provide some legal context to the Authorship Attribution Workshop (“conference”). In particular, I want to offer some pragmatic observations on what courts will likely demand of forensic linguistics experts and tentatively suggest what the field should aspire to in both the short and long run.

Independent Judicial Research In The "Daubert" Age, Edward K. Cheng

Vanderbilt Law School Faculty Publications

The Supreme Court's Daubert trilogy places judges in the unenviable position of assessing the reliability of often unfamiliar and complex scientific expert testimony. Over the past decade, scholars have therefore explored various ways of helping judges with their new gatekeeping responsibilities. Unfortunately, the two dominant approaches, which focus on doctrinal tests and external assistance mechanisms, have been largely ineffective. This Article advocates for a neglected but important method for improving scientific decision making-independent judicial research. It argues that judges facing unfamiliar and complex scientific admissibility decisions can and should engage in independent library research to better educate themselves about the …

Does Frye Or Daubert Matter? A Study Of Scientific Admissibility Standards, Edward K. Cheng, Albert Yoon

Vanderbilt Law School Faculty Publications

Nearly every treatment of scientific evidence begins with a faithful comparison between the Frye and Daubert standards. Since 1993, jurists and legal scholars have spiritedly debated which standard is preferable and whether particular states should adopt one standard or the other. These efforts beg the question: Does a state's choice of scientific admissibility standard matter? A growing number of scholars suspect that the answer is no. Under this theory, the import of the Supreme Court's Daubert decision was not in its doctrinal standard, but rather in the general consciousness it raised about the problems of unreliable scientific evidence. This Article …

Doubts About Daubert: Psychiatric Anecdata As A Case Study, Christopher Slobogin

Vanderbilt Law School Faculty Publications

In Daubert v. Merrell Dow Pharmaceuticals Inc., the Supreme Court sensibly held that testimony purporting to be scientific is admissible only if it possesses sufficient indicia of scientific validity. In Kumho Tire Co. v. Carmichael, the Court more questionably held that opinion evidence based on "technical" and "specialized" knowledge must meet the same admissibility threshold as scientific testimony. This Article addresses the implications of these two decisions for opinion evidence presented by mental health professionals in criminal trials.