to the central imperatives of the other’s way of doing business, and it is likely that neither will be shown in its best light. The Daubert decision is an attempt (not the first, of course) to regulate that encounter. Judges are asked to decide the “evidential reliability” of the intended testimony, based not on the conclusions to be offered, but on the methods used to reach those conclusions.

In particular, Daubert says, the methods should be judged by the following four criteria:

  1. The theoretical underpinnings of the methods must yield testable predictions by means of which the theory could be falsified.
  2. The methods should preferably be published in a peer-reviewed journal.
  3. There should be a known rate of error that can be used in evaluating the results.
  4. The methods should be generally accepted within the relevant scientific community.

In reading these four illustrative criteria mentioned by the Court, one is struck immediately by the specter of Karl Popper looming above the robed justices. (It is no mere illusion. The dependence on Popper is explicit in the written decision.) Popper alone is not enough, however, and the doctrine of falsification is supplemented by a bow to the institution of peer review, an acknowledgment of the scientific meaning of error, and a paradigm check (really, an inclusion of the earlier Frye standard).21

The Daubert case and two others (General Electric v. Joiner,22 and Kumho Tires v. Carmichael23) have led to increasing attention on the part of judges to scientific and technical issues and have led to the increased exclusion of expert testimony, but the Daubert criteria seem too general to resolve many of the difficult decisions the courts face when considering scientific evidence. Nonetheless, despite some inconsistency in rulings by various judges, the Daubert decision has given the courts new flexibility, and so far, it has stood the test of time.

All in all, I would give the decision pretty high marks.24 The justices ventured into the treacherous crosscurrents of the philosophy of science—where even most scientists fear to tread—and emerged with at least their dignity intact. Falsifiability may not be a good way of doing science, but it is not the worst a posteriori way to judge science, and that is all that’s required here. At least they managed to avoid the Popperian trap of demanding that the scientists be skeptical of their own ideas.

21. In Frye v. United States, 293 F. 1013, 1014 (D.C. Cir. 1923), the court stated that expert opinion based on a scientific technique is inadmissible unless the technique is “generally accepted” as reliable in the relevant scientific community.

22. 522 U.S. 136 (1997).

23. 526 U.S. 137 (1999).

24. For a contrary view, see Gary Edmond & David Mercer, Recognizing Daubert: What Judges Should Know About Falsification, 5 Expert Evid. 29–42 (1996).



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