Which standard governs the admissibility of expert witness testimony in US federal legal proceedings?

The standard that governs the admissibility of expert witness testimony in US federal legal proceedings is known as the Daubert standard. This standard emerged from the Supreme Court case Daubert v. Merrell Dow Pharmaceuticals, Inc., which established a framework for determining whether an expert's scientific testimony is based on reliable principles and methods that are valid and applicable to the facts of the case.

Under the Daubert standard, judges serve as gatekeepers, evaluating not just the methodology used by the expert but also its relevance to the issues at hand. Key considerations include whether the theory or technique has been tested, subjected to peer review, has a known error rate, and is generally accepted in the relevant scientific community. This framework is designed to ensure that only expert testimony that meets rigorous scientific standards is presented in court, thereby enhancing the reliability of the evidence considered by the trier of fact.

The other options mentioned do not reflect the current federal standard for admissibility. The Frye standard, for instance, was an earlier standard based on whether scientific evidence is generally accepted in the relevant field, but it has been largely replaced by the Daubert standard in federal courts. The references to Brier and Kennedy do not correspond to recognized standards of expert testimony admissibility in legal proceedings