the animal and chemical structure research on which
the plaintiffs’ experts based their opinions was irrele-
vant and that the results of the meta-analysis had not
been generally accepted within the field of epidemiol-
ogy, because it had not been peer-reviewed or pub-
lished. Thus, the District Court relied on the Frye
standard for excluding the testimony proffered by the
plaintiffs. The plaintiffs appealed the District Court’s
decision, arguing that the court had improperly used
the Fryestandard when judging the admissibility of its
expert evidence as Frye had been replaced by the
FRE. The Supreme Court agreed to hear the case and
ruled in favor of the petitioners, agreeing that the FRE
had replaced Frye as the appropriate standard for
judging the admissibility of expert testimony.
In its decision, the Supreme Court outlined a two-
pronged test for the admissibility of expert testimony.
One prong required that expert testimony must be rel-
evant to an issue before the court to be admissible.
The second prong required that the expert testimony
be reliable. In essence, the Supreme Court ruled that
judges must evaluate whether scientific evidence is
based on reliable methodology rather than relying on
general acceptance in the scientific community to
determine whether the testimony is admissible. The
court sought to help judges who lack the scientific
training to make these determinations by offering sug-
gestions for criteria that could be used to evaluate
research. For one, the court suggested that judges
examine whether the theory or hypothesis on which
the research is based can be falsified or tested.
Second, the court stated that another way to assess
whether the proffered evidence is reliable is to deter-
mine if it has been peer-reviewed and published.
Third, judges should evaluate whether the technique
in question has a known or potential error rate.
Finally, although no longer a necessary and sufficient
characteristic for admissibility, the Court suggested
that judges could still use general acceptance as a fac-
tor in determining whether or not to admit testimony.
The Daubertdecision held that the admissibility of
scientific evidence depends on its scientific validity.
The guidelines for judging the admissibility of scien-
tific evidence promulgated in Daubert shifted the
focus of the admissibility decision from determining
whether the evidence was accepted by other scientists
to an examination of the methods of the research on
which experts base their opinions. Essentially, the
decision in Daubert transferred the role of gatekeeper
from the relevant scientific community to the trial
court judge.GGeenneerraall EElleeccttrriicc CCoo.. vv.. JJooiinneerrAlthough the Daubertdecision settled the controversy
regarding the appropriate standards by which judges
should evaluate the admissibility of scientific expert
testimony, there was disagreement over the standard
to be used when reviewing such decisions. The
Supreme Court addressed this question in General
Electric Co. v. Joiner (1997).In this case, Robert
Joiner, the plaintiff, had brought suit alleging that his
development of lung cancer was influenced by his
exposure to dielectric fluid contaminated with poly-
chlorinated biphenyls while on the job at General
Electric. Joiner sought to introduce testimony from
several experts that exposure to polychlorinated
biphenyls, not his history as a smoker, caused the
early onset of his lung cancer, but the District Court
ruled that the experts’ evidence was mere speculation
and, therefore, inadmissible. On appeal, the Eleventh
Circuit Court of Appeals applied a stringent standard
of review when assessing this ruling and decided that
the District Court had been wrong to exclude the
expert testimony. They believed that the FRE showed
preference for the admission of expert testimony and
based on this analysis concluded that the District
Court should have allowed the expert testimony.
However, the United States Supreme Court reversed
the decision of the Eleventh Circuit Court, ruling
that the appellate court had applied the wrong stan-
dard of review. The Court determined that the proper
standard of review for decisions regarding the admis-
sibility of expert testimony should be whether the
judge abused his or her discretion by excluding the
expert testimony. The Court explained that although
the FRE may provide for the admission of a greater
variety of scientific testimony, the trial court judge
still retains his or her role as gatekeeper and must
evaluate the reliability of the proffered expert evi-
dence to approve or deny its admissibility rather than
abdicating this responsibility due to the perceived lib-
eral thrust of the FRE. The Supreme Court then ruled
that the District Court had reasonable grounds to
question the reliability of the expert testimony prof-
fered by Joiner and had not abused its discretion in
excluding it.KKuummhhoo TTiirree CCoommppaannyy vv.. CCaarrmmiicchhaaeell
Although Daubert provided trial court judges with
guidance regarding the factors to be considered
when determining the admissibility of scientific expertExpert Psychological Testimony, Admissibility Standards——— 273E-Cutler (Encyc)-45463.qxd 11/18/2007 12:42 PM Page 273