Also known as:Trilogy · Steelworkers Trilogy · Steelworkers' Trilogy
Written by attorneys · grounded in primary & secondary sources — see below
2 senses
1
in evidence law
A set of three Supreme Court decisions establishing the standards for admissibility of expert testimony. A trial court acts as gatekeeper to ensure both the reliability of an expert's principles and methods and the reliable application of those methods to the facts of the case. Appellate courts review a district court's decision to admit or exclude such testimony for abuse of discretion.
2
Sense 1
1
in evidence law
A set of three Supreme Court decisions establishing the standards for admissibility of expert testimony. A trial court acts as gatekeeper to ensure both the reliability of an expert's principles and methods and the reliable application of those methods to the facts of the case. Appellate courts review a district court's decision to admit or exclude such testimony for abuse of discretion.
Sources & Authorities· 1 primary source
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Cases
Sense 2
2
in patent law
Three 1966 Supreme Court opinions that interpreted the nonobviousness requirement under 35 U.S.C. § 103. The decisions replaced earlier subjective standards such as synergy or flash of genius with an objective inquiry based on the knowledge of a person of ordinary skill in the art.
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Hornbooks
Examples
Put it into practice
Test Yourself
2
Practice Essays2
in patent law
Three 1966 Supreme Court opinions that interpreted the nonobviousness requirement under 35 U.S.C. § 103. The decisions replaced earlier subjective standards such as synergy or flash of genius with an objective inquiry based on the knowledge of a person of ordinary skill in the art.
Each sense below has its own examples, sources, and questions.
Practice Essays
Examples1
Expert Exclusion Upheld on Appeal
Tracy Torres sued Terra Financial after a software error caused her investment account to liquidate prematurely. She offered Theo Thomas, a computer scientist, to testify that the algorithm contained a design flaw. Thomas relied on a handful of informal laptop runs and his own unverified benchmarking script. The district court excluded the testimony after finding an impermissible analytical gap between the limited data and the defect conclusion. The court of appeals affirmed, holding that the exclusion fell within the trial court's gatekeeping discretion.
Frequently Asked3
Which three cases form the Daubert trilogy?+
The trilogy consists of Daubert v. Merrell Dow Pharmaceuticals, General Electric Co. v. Joiner, and Kumho Tire Co. v. Carmichael. These decisions together define the trial court's gatekeeping role over expert testimony and the abuse-of-discretion standard on appeal.
Supporting sources
What standard of review applies to a district court's exclusion of expert testimony under Joiner?+
Appellate courts review the decision for abuse of discretion. Reversal is warranted only when the exclusion is manifestly erroneous.
Supporting sources
How does the analytical-gap principle operate in expert admissibility decisions?+
A court may exclude testimony when the expert's conclusions rest on data too remote from the opinion offered. The gap is assessed by examining whether the methodology is reliable and whether the opinion is adequately supported by the facts actually considered.
Supporting sources
1
Nonobviousness Challenge Resolved
Triumph Manufacturing obtained a patent on a new gear assembly. Tundra Resources challenged the patent, arguing that the combination of known elements would have been obvious. The court applied the framework from the three 1966 decisions, examining the scope of the prior art, the differences between the claimed invention and that art, and the level of ordinary skill. Because the combination produced unexpected results beyond the knowledge of a person of ordinary skill, the court upheld the patent.
Frequently Asked1
What does the patent trilogy address?+
The three 1966 opinions interpret the nonobviousness requirement of 35 U.S.C. § 103 and replace earlier subjective invention tests with an objective inquiry keyed to a person of ordinary skill in the art.
Supporting sources
EvidenceRelevancy and reasons for excluding relevant evidence · Expert testimonyUBEIntermediate