Daubert v Merrel Dow Pharmaceutical 113 S.Ct 2786; 125 L. Ed.2d 469
In a 1993 decision, the Supreme Court held that the Federal Rules of Evidence set the
standard for the admissibility of scientific evidence, proffered by an expert witness.
This case is important to both the expert and the practitioner since more expert opinions
are coming under fire using the Daubert rule [see accompanying article].
The case involves two minor children and their parents who alleged in their suit that the children's serious birth defects had been caused by the mother's prenatal ingestion of Bendectin, a prescription drug marketed by the respondents, Merrell Dow Pharmaceuticals.
The District Court granted respondent summary judgement based on a well-credentialed expert's affidavit concluding, upon reviewing the extensive published scientific literature on the subject, that maternal use of Bendectin has not been shown to be a risk factor for human birth defects.
Although petitioners had responded with the testimony of eight other well-credentialed experts, who based their conclusion that Bendictin can cause birth defects on animal studies, chemical structure analyses, and unpublished "reanalysis" of previously published human statistical studies, the trial court determined that this evidence did not meet the applicable "general acceptance" standard for the admission of expert testimony.
The Court of Appeals agreed and affirmed.
The Supreme Court reversed holding that the Federal Rules of Evidence provide the standard for admitting expert scientific testimony in a federal trial. The "general acceptance" test was superseded by the adoption of the Rules of Evidence. Nothing in the Rules as a whole or in the text and drafting history of Rule 702 (see side bar), which specifically governs expert testimony, gives any indication that "general acceptance" is a necessary precondition to the admissibility of scientific evidence. Moreover, such a rigid standard would be at odds with the Rules' liberal thrust and their general approach of relaxing the traditional barriers to "opinion" testimony.
The Court stated that the Rules - especially Rule 702 - place appropriate limits on the admissibility of purportedly scientific evidence by assigning to the trial judge the task of ensuring that an expert's testimony both rests on a reliable foundation and is relevant to the task at hand.
The reliability standard is established by Rule 702's requirement that an expert's testimony pertain to "scientific . . . knowledge." The adjective "scientific" implies a grounding in science's methods and procedures, while the word "knowledge" connotes a body of known facts or ideas inferred from such facts or accepted as true on good grounds.
The relevance standard requires that the testimony "assist the trier of fact to understand the evidence or to determine a fact in issue" by demanding a valid scientific connection to the pertinent inquiry as a precondition to its admissibility.
Faced with a proffer of expert scientific testimony under Rule 702, the trial judge, pursuant to Rule 104(a), must make a preliminary assessment of whether the testimony's underlying reasoning or methodology is scientifically valid and properly can be applied to the facts at issue. Many considerations will bear on the inquiry, including whether the theory or technique in question can be (and has been) tested, whether it has been subjected to peer review and publication, its known or potential error rate, and the existence and maintenance of standards controlling its operation, and whether it has attracted widespread acceptance within a relevant scientific community. The inquiry is a flexible one, and its focus must be solely on principles and methodology, not on the conclusions that they generate.
Cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof, rather than wholesale exclusion under an uncompromising "general acceptance" standard, is the appropriate means by which evidence based on valid principles may be challenged. That even limited screening by the trial judge, on occasion, will prevent the jury from hearing of authentic scientific breakthroughs is simply a consequence of the fact that the Rules are not designed to seek cosmic understanding but, rather, to resolve legal disputes.
What do these words taken from the case syllabus mean to the expert. While the fact situation of the case certainly involves complex scientific evidence and laboratory tests, such is not always the case. In less complex situations such as a simple slip or trip, the expert can still expect to be closely examined on the "tests" which he applied and the standards used in arriving at his opinions. "Tests" do not necessarily mean those conducted in a laboratory or with scientific instruments. It means the manner of examination of the evidence by the expert in arriving at the testimonial opinions. For instance, did he feel, smell, observe or measure the stairway, deck or coaming on which a person slipped or tripped. Were the methods he used similar to those used by his peers. Are there standards against which he and others measured their findings and opinions.
These were the considerations in the accompanying article in which a maritime expert was disqualified as an expert in a case involving a personal watercraft.
The expert must be prepared to answer these questions in order to step over the threshold of qualification and acceptance by the court of his expert opinions.
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