This post continues the discussions in earlier posts about evidentiary standards for admissibility of health and safety studies on nanomaterials under both the Frye standard and the Daubert standard. I will resume the reliability discussion here, this time focusing on the reliability standards applied in the federal courts and other Daubert jurisdictions.
Under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), reliability of expert scientific evidence is determined in relation to four factors. These four “general observations” set forth in the Daubert decision were intended to provide guidance to the trial court making a decision about admissibility of expert scientific evidence. All four need not be favorable to the party seeking admission of the evidence for the evidence to be ruled admissible. The Supreme Court has said that when it comes to scientific studies, evidentiary reliability is the equivalent of scientific validity. What makes a scientific study (and the expert testimony relying on it) valid? The Supreme Court set forth these “general observations”:
(1) Whether the scientific theory or technique on which the evidence is based has been tested (presumably by the scientific method);
(2) Whether the study has been published or has undergone another form of peer review;
(3) The known or potential rate of scientific error associated with the methodology;
(4) Whether the methodology has achieved general acceptance in its field.
Although these factors reduce the weight of general acceptance (the sole Frye criterion) in the admissibility analysis, the reality is that the Daubert test has raised the bar in litigation for plaintiffs seeking to have their scientific proof admitted. These factors are often applied strictly.
Will scientific studies on the health and safety effects of nanomaterials be treated differently under the Daubert reliability analysis than under the Frye general acceptance test? The primary difficulty under Daubert, as under Frye, is the newness of the studies.
Although the Supreme Court in Daubert said that the focus of the reliability analysis should be on the scientific methodology or technique – and not on the conclusions reached – the Court subsequently modified that statement. In General Electric Co. v. Joiner, 522 U.S. 136 (1997), the Supreme Court said that “conclusions and methodology are not entirely separate from one another,” thus inviting the trial court to consider the conclusion and whether it constitutes the kind of novel theory that may not be admissible.
It may be true generally that newer methodologies may not have been sufficiently tested, peer reviewed, or accepted in the relevant scientific community, and that they could have a potentially high (or unknown) rate of error. But one issue that will need to be sorted out in the era of nanostudies will be whether the methodologies for these studies consist of tried-and-true testing methods or, in contrast, will be viewed as novel because of their focus on materials at the nanoscale. This distinction could make a critical difference in whether such studies will be admitted in litigation in a Daubert jurisdiction. Tried-and-true carries more admissibility weight.
Perhaps one way to look at this issue – and one that is relevant to the emerging studies of nanomaterials – is the way that a federal district court analyzed the problem in Smith v. General Electric Co., 2004 WL 870832 (D. Mass. 2004). When confronted with novel and admittedly “controversial” studies, the court concluded that the experts were “serious scientists with controversial views that are in many respects on the periphery of the mainstream, but views that are not so divorced from a scientific method of investigation that they can be dismissed as quackery or armchair conjecture.” While the district court was likely correct in observing that Daubert did not require or perhaps even empower a court to “determine which of several competing scientific theories has the best provenance,” many would reject the flexible view of Daubert applied in Smith.
Reliability is only part of the admissibility analysis for scientific studies articulated by the Supreme Court in Daubert. Relevance of the evidence is equally important, and my next post on the subject will look at the relevance of scientific evidence as it has been explained by the Supreme Court in Daubert and Joiner (mentioned above).
