Abstract
The first section of this paper explains why assessing the worth of expert testimony poses special epistemological difficulties. The second traces the history of the various rules and procedures by means of which the U.S. legal system has tried to ensure, or at least control, the quality of the expert testimony on which it so often relies—from the Frye Rule, the Federal Rules of Evidence, and the Daubert trilogy to recent constitutional cases regarding the appearance of forensic witnesses in court and experiments with court-appointed experts and scientific education for judges. The third and final section suggests some lessons to be learned from the limited success of these efforts, and explores what might be better strategies going forward.