Also known as:Daubert · Daubert standard · Daubert test
Written by attorneys · grounded in primary & secondary sources — see below
A standard for determining the admissibility of expert testimony under Federal Rule of Evidence 702. Federal district courts must act as gatekeepers to ensure that the testimony is both relevant and reliable. Reliability is assessed through a flexible case-specific inquiry that may consider factors such as testability, peer review and publication, known or potential error rate, existence of controlling standards, and general acceptance in the relevant field.
Sources & Authorities
How it applies
Common Examples
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Aerospace Simulation Model Challenged
Suzanne sued Prime Orbit after a pilot died in a crash. Prime Orbit offered an aerospace engineer whose proprietary fluid-dynamics simulation had undergone internal university testing and produced results consistent with limited wind-tunnel data. Suzanne moved to exclude the testimony because the model lacked peer review in accident-reconstruction literature and had no known error rate for real-world crashes. The district court denied the motion and admitted the testimony after finding the underlying principles sound and the assumptions subject to cross-examination.
Computer Scientist Testimony Excluded
United Cloud offered Owen to testify that its algorithm did not infringe Pacific Logic's patent. Owen relied on a self-developed benchmarking script and informal laptop tests that had never been peer-reviewed or validated outside the company. Pacific Logic moved to exclude the testimony because the extrapolation from limited data created an analytical gap. The district court held a Daubert hearing and excluded the testimony in full.
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Cases
Course Outlines
Study Supplements
Financial Economist Event Study
East Investments retained Rodney to quantify damages in a securities fraud case through an event study using a customized small-cap index and selective exclusion of trading days. Cedar Equity showed that substituting the S&P 500 and retaining two excluded days reduced the damages calculation by 28 percent. The district court admitted the testimony after finding the methods generally accepted and tested through alternative specifications.
Silicone Implant Degradation Expert
A plaintiff offered an expert to testify about degradation of silicone gel breast implants. The defendant moved to exclude the testimony on the ground that the expert's methodologies were unscientific and unreliable. The court evaluated the expert's approach under the flexible reliability framework before deciding admissibility.
Plaintiffs offered an expert to show a pattern of discriminatory practices across thousands of stores. The defendant challenged the expert's regression model for failing to account for store-level variations. The court conducted a case-specific review of the methodology's reliability before ruling on admissibility.
Wal-Mart Stores, Inc. v. Dukes564 U.S. 338 (2011)
Hearsay Statement Reliability
The government offered a statement against penal interest through an expert who interpreted coded language. The defendant objected that the expert's interpretive method lacked sufficient validation. The court assessed whether the methodology rested on reliable principles before allowing the testimony.
Williamson v. United States512 U.S. 594 (1994)
Common questions
Frequently Asked
3
What is the trial court's role when expert testimony is offered under Rule 702?+
The trial court must act as gatekeeper to ensure the testimony is both relevant and reliable before it reaches the jury. The court conducts a preliminary assessment of the expert's reasoning and methodology.
Supporting sources
Does the Daubert reliability analysis apply only to scientific experts?+
No. The analysis applies to all expert testimony based on technical or other specialized knowledge. Courts retain discretion to consider the traditional factors or other appropriate indicia of reliability depending on the nature of the expertise.
Supporting sources
What standard of review applies to a district court's Daubert ruling?+
Appellate courts review the decision to admit or exclude expert testimony for abuse of discretion. A court may exclude testimony when there is too great an analytical gap between the data and the opinion offered.
Supporting sources
509 U.S. 579, 592 (1993)Evidence
Daubert v. Merrell Dow Pharmaceuticals, Inc. <!-- acedexams opinion md v1 -- Case information - Citation: 509 U.S. 579, 592 (1993) Majority opinion Opinion of Judge Kozinski Michael H. Gottesman, Georgetown…