Also known as:Daubert factor · Daubert's factors · Daubert test · Daubert standard · Daubert criteria
Written by attorneys · grounded in primary & secondary sources — see below
A set of nonexclusive considerations that federal courts use to assess the reliability of expert testimony offered under Federal Rule of Evidence 702. Courts evaluate whether the expert's theory or methodology has been tested, subjected to peer review and publication, possesses a known or potential error rate, is governed by standards controlling its operation, and enjoys general acceptance in the relevant field. The inquiry remains flexible and case-specific rather than a rigid checklist.
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How it applies
Common Examples
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Acoustics Expert in Wind Farm Suit
Daphne Doyle and other residents sued Zephyr Wind Corp. for nuisance, claiming low-frequency turbine noise caused health problems. Zephyr offered an acoustics consultant whose hybrid method combined short-term measurements with subjective surveys never used as a standard in the field. The trial judge conducted a Daubert hearing and excluded the testimony after finding insufficient indicia that the novel technique rested on reliable principles or had been reliably applied.
Computer Scientist in Patent Dispute
Pacific Logic sued United Cloud for patent infringement over facial recognition algorithms. United Cloud proffered a computer scientist who relied on a self-developed benchmarking script and informal laptop tests to claim industry-leading accuracy. The district court held a Daubert hearing, found the unreviewed internal methods lacked testing, peer review, or a known error rate, and excluded the testimony as unreliable.
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Practice Questions4
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Common questions
Frequently Asked
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Do the Daubert factors apply only to scientific expert testimony?+
No. The reliability inquiry extends to all expert testimony based on technical or other specialized knowledge. Courts retain discretion to consider the listed factors or any other appropriate indicia of reliability when the expertise is engineering, technical, or experience-based rather than purely scientific.
Supporting sources
Must an expert satisfy every Daubert factor for the testimony to be admitted?+
No. The factors are illustrative and nonexclusive. A court may admit testimony when several factors support reliability even if others are unsatisfied, provided the overall methodology is reliable and has been reliably applied to the facts of the case.
Supporting sources
What happens when an expert's method has never been tested or peer-reviewed?+
The absence of testing and peer review weighs heavily against admissibility. A court may still admit the testimony if other indicia such as internal validation, consistent field use, or established underlying principles supply sufficient reliability under a flexible, case-specific analysis.
Supporting sources
EvidenceRelevancy and reasons for excluding relevant evidence · Expert testimonyUBEIntermediate