Judicial gatekeeping and the social construction of the admissibility of expert testimony.

Content analysis of 192 U.S. District Court cases was conducted to investigate judges' evaluations of expert characteristics and evidence characteristics for toxicology, psychological/psychiatric, and damages testimony. Judges evaluated more expert characteristics, but not more evidence characteristics, as the number of months post-Daubert increased (Hypotheses 1 and 2). More evidence characteristics were evaluated when evidence was quantitatively rather than qualitatively based (Hypothesis 3). The greatest number of evidence characteristics examined was for toxicology evidence (Hypothesis 4). Fewer expert characteristics were evaluated for admissible evidence, but more evidence characteristics were evaluated for inadmissible evidence (Hypothesis 5). All analyses were significant at .05. Implications for judges, attorneys, and experts are discussed.