Daubert v. Merrell Dow Pharmaceuticals, Inc.

Jason Daubert and Eric Schuller were born with serious birth defects. Their families sued Merrell Dow Pharmaceuticals, alleging that the mothers' ingestion of Bendectin, an anti-nausea drug, during pregnancy caused the defects. Merrell Dow moved for summary judgment, presenting an expert affidavit reviewing over 30 published studies finding no link between Bendectin and birth defects. The plaintiffs countered with eight experts who relied on in vitro studies, animal studies, and reanalysis of prior epidemiological data, none of which had been published or subjected to peer review.

Justice Blackmun, writing for the majority, reasoned that the Federal Rules of Evidence did not incorporate a rigid 'general acceptance' standard. Rule 702, as drafted, requires only that testimony assist the trier of fact and be based on 'scientific knowledge,' which implies a grounding in the methods and procedures of science. The Court identified four non-exclusive factors: whether the theory or technique can be and has been tested; whether it has been subjected to peer review and publication; the known or potential error rate; and the degree of acceptance within the relevant scientific community. The gatekeeping role assigned to the trial judge is guided by Rule 104(a), which gives the court broad discretion in making preliminary determinations of admissibility. The standard is flexible and focuses on principles and methodology, not on the conclusions generated.

Daubert became the controlling standard for expert testimony in all federal courts and was subsequently adopted by a majority of state courts. The decision expanded judicial gatekeeping responsibilities and led to extensive satellite litigation over the admissibility of expert testimony. Congress codified and strengthened the Daubert framework through the 2000 amendment to Rule 702.