EXPERT EVIDENCE AND THE CHALLENGE FOR THE COURTS
The quality of expert evidence in the courtroom is a highly controversial subject. Expert evidence is a critical component of many types of civil litigation, and some critics have argued that too much “junk science” is admitted into evidence. In their view, juries have often been overly influenced by expert evidence that is not based on a solid scientific footing. Other critics have argued that novel expert evidence or evidence about which reasonable experts could disagree is too often barred from cases and that injured plaintiffs are not compensated as a result In June 1993, the U.S. Supreme Court responded to the growing controversy about expert evidence by issuing the Daubert decision,1 which clarified the role of federal judges as “gatekeepers” and established a new standard for how judges were to decide whether expert evidence was to be admitted. This report sheds light on how the standards for admitting expert evidence have changed since Daubert and how the parties proposing and challenging evidence have responded to those changes.
Before Daubert, there was not a universally followed standard for determining the admissibility of expert evidence in the federal courts. The two leading approaches were based on relevance and general acceptance in the scientific community (Giannelli, 1994). Advocates of the relevance standard argued that expert evidence should be admitted if relevant, as long as the expert was properly qualified and admission would not prejudice or mislead the jury,2 They believed that “junk science” could be excluded by ensuring that experts were qualified (Giannelli, 1994).3 The general acceptance standard, also known as the Frye standard in reference to the 1923 federal decision that established the principle, required not only relevance and proper expert qualifications but also “general acceptance in the particular field in which it [the evidence] belongs”.4 Although the two standards were in conflict, there was little debate about the issue in the 1950s and 1960s because “controversy concerning the validity of scientific techniques did not exist at that time” (Giannelli, 1994, p. 2009).____________________