For purposes of determining whether a theory or technique is scientific knowledge under Fed. R. Evid. 702, in the case of a particular scientific technique, the court ordinarily should consider the known or potential rate of error, and the existence and maintenance of standards controlling the technique's operation. Finally, "general acceptance" can yet have a bearing on the inquiry. A reliability assessment does not require, although it does permit, explicit identification of a relevant scientific community and an express determination of a particular degree of acceptance within that community. Widespread acceptance can be an important factor in ruling particular evidence admissible, and a known technique which has been able to attract only minimal support within the community, may properly be viewed with skepticism. The inquiry envisioned by Rule 702 is a flexible one. Its overarching subject is the scientific validity -- and thus the evidentiary relevance and reliability -- of the principles that underlie a proposed submission. The focus, of course, must be solely on principles and methodology, not on the conclusions that they generate.
Petitioners were children with serious birth defects. Their parents alleged that the mothers' ingestion of respondent's drug caused defects. Respondent brought a motion for summary judgment, supported by proof that the drug did not cause defects. Petitioners responded with expert opinions that the drug did cause defects. The opinions were based on a reanalysis of previously published studies stating the drug did not cause defects. The trial court granted respondent's motion, holding petitioners' scientific evidence was inadmissible because the reanalyzed studies were not reliable where they had not been published. Petitioners appealed. The Court vacated and remanded.
Did the expert testimony presented meet the standards for admitting expert scientific testimony in a federal trial?
The summary judgment was reversed where expert opinions were admissible to show respondent's drug caused birth defects despite the fact that the experts' analysis had not been published or subject to peer review. A technique upon which an expert opinion was based did not have to be generally accepted as reliable as a precondition to the opinion's admission as long as the standards of reliability and relevance under the federal evidence rules were met. The common law standard for determining reliability of scientific evidence was inapplicable where federal evidence rules superceded the common law. Publication or peer review of the experts' recalculation was thus unnecessary.