Also known as:reliability standard · scientific evidence reliability · technical evidence reliability · reliability of scientific evidence · Daubert reliability · FRE 702 reliability
Written by attorneys · grounded in primary & secondary sources — see below
A gatekeeping requirement imposed on trial courts under Federal Rule of Evidence 702 that expert testimony based on scientific, technical, or other specialized knowledge must rest on reliable principles and methods reliably applied to the facts of the case. Courts employ a flexible, case-specific inquiry that may draw on the traditional Daubert factors or any other appropriate indicia of reliability suited to the particular field of expertise.
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Cases
Casebooks
How it applies
Common Examples
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Engineer Testimony on Machine Guard
Rosa Ruiz sued Apex Pressworks after a factory press crushed her hand. Apex offered a mechanical engineer who relied on proprietary modeling software and personal inspections to conclude that the safety guard design was adequate. Ruiz moved to exclude the testimony because the methods lacked peer-reviewed studies. The court denied the motion after conducting a flexible reliability inquiry that considered industry validation of the software and consistency with established engineering principles.
Forensic DNA Analyst Report
Rowan Russell faced criminal charges after a lab report linked him to biological evidence recovered at a crime scene. The prosecution offered testimony from a DNA analyst who used an internal benchmarking script and unreviewed test results to support the match. Russell moved to exclude the opinion for lack of external validation or peer review. The court excluded the testimony after finding that the self-developed methods created too great an analytical gap between the data and the conclusions offered.
Common questions
Frequently Asked
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Does the reliability standard apply only to traditional laboratory science?+
No. The standard extends to all expert testimony based on technical or other specialized knowledge. A court must therefore evaluate engineering opinions, experience-based police training matrices, and similar non-scientific expertise under the same flexible reliability framework.
Supporting sources
May a court admit expert testimony that rests solely on an expert's untested personal observations?+
A court may consider extensive practical experience and consistent field application as indicia of reliability when the expertise is technical or specialized. The absence of empirical testing or peer review does not automatically render the testimony inadmissible if other appropriate markers of trustworthiness are present.
What happens when an expert's methodology was created specifically for the litigation?+
Litigation-driven methods receive heightened scrutiny because they lack external validation. A court may still admit the testimony if the underlying principles are established and accepted within the relevant field, but the absence of testing, peer review, or replication often supports exclusion.
Supporting sources
How does the reliability standard interact with the requirement of reliable application to the facts?+
Even when the underlying principles are sound, the expert must reliably apply those principles to the case-specific facts. An impermissible analytical gap between the data generated and the opinions offered justifies exclusion under Rule 702(d).
Supporting sources
reliability standard
to all "
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technical
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Daubert
referred only to "
scientific
" knowledge. But as the Court there…
, footprint comparisons); State v. Hall , 297 N.W.2d 80 (Iowa 1980) (en banc) (novelty of the new invention and the existence of a specialized literature are relevant to the admissibility…
EvidenceRelevancy and reasons for excluding relevant evidence · Expert testimonyUBEFoundational