Daubert Trilogy pt. 3: Kumho Tire

Plaintiffs-Respondents are the Carmichael family who were involved in a severe automobile accident after their rear right tire failed. That this failure caused the accident and the injuries to the family are not in dispute, however the plaintiffs claim that the failure was the result of a manufacturing defect.  To support this claim plaintiffs proffered the testimony of one expert witness, an engineer employed as a tire consultant. The consultant testified that the tread had been worn bald and punctured by a nail before the accident. The testimony of this expert was about causation under Fed. R. Evid. 702 an 403. Because no other evidence was presented by plaintiffs on causation, the district court granted defendant’s motion for summary judgment. The 11th Circuit reversed and remanded, holding that the court below was in error in applying the Daubert standard to the expert’s testimony, because Daubert should only apply to scientific and not to non-scientific evidence.

Issue Areas:

Sound Science


Kumho Tire Co. v. Carmichael (U.S.) (merits stage)

Question(s) Presented:

Did the district court err in applying the Daubert standard to plaintiff’s expert’s testimony; do the Daubert standards apply broadly to expert testimony that applies a body of knowledge (especially that gleaned from a scientific process) to a practical problem?

Additional Background:

Daubert v. Merrill Dow Pharmaceuticals, 509 U.S. 579, (1993). General Electric Co. v. Joiner, 118 S.Ct. 512, (1997).

ALF’s Amicus Brief:

Daubert itself, and Joiner that followed, applied the “Daubert factors” to the assessment of causation of disease in medical science. The Supreme Court did not suggest that those principles or the scientific method itself are limited to medical science, basic science, or any other science. Indeed, those cases emphasized that Rule 702 and the trial court’s responsibility for ensuring that expert testimony that purports to be based on “scientific, technical, or other specialized knowledge” is reliable. The Daubert court emphasized that the word “knowledge” applies to “any body of known facts or to any body of ideas interred from such facts or accepted as truths on good grounds.” The test for reliability of expert testimony applying such knowledge is:

1. whether the expert’s theory can be or has been tested;

2. whether the theory has been subject to peer review and publication;

3. the known or potential rate of error of a technique when applied;

4. the existence and maintenance of standards and controls;

5. the degree to which the technique or theory has been generally accepted.

Daubert charges district courts applying these factors as “gatekeepers” to ensure reliability of expert testimony submitted to the jury. Rule 702 ensures that the standards that scientists have in their professional work are applied to expert testimony in the court room. Because engineering relies on the scientific method, and because “failure testing” makes scientific factual claims related to causation, the methods used by an engineer in his “failure tests” should be subject to the same scrutiny that other professional engineers making scientific claims are subject to.

The expert at issue claimed that 4 factors were indicative of “overdeflection” which was the defect that caused the plaintiff’s tire to pop. However, he does not offer evidence as to why these four factors should constitute a “failure test,” and these factors therefore have not been tested. His method of testing these arbitrarily selected criteria is to visually inspect the tire, which is not an objectively verifiable or repeatable method of measure. Carlson was not published, nor could he cite to any publication which employed his methods. Because this expert was the sole practitioner of this subjective testing method, no error rate could be estimated, nor could this error rate be mitigated by controls. Being the sole practitioner of his subjective test, this method has not, nor could it ever gain side spread acceptance in the engineering community.

ALF asks the Supreme Court to reaffirm the applicability of Daubert, and overturn the decision of the 11th Circuit to allow junk science to pollute the courtroom.


In a favorable decision the Supreme Court held that Daubert applied broadly to scientific claims of causation.

Date Originally Posted: August 12, 1998

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