Daubert and its progeny stand for several essentials on expert testimony.
First, the Judge is gatekeeper: Under Rule 702, the task of “gatekeeping”, or assuring that scientific expert testimony truly proceeds from “scientific knowledge”, rests on the trial judge.
Relevance and reliability: This requires the trial judge to ensure that the expert’s testimony is “relevant to the task at hand” and that it rests “on a reliable foundation.” The Judge must find it more likely than not that the expert’s methods are reliable and reliably applied to the facts at hand.
Scientific knowledge = scientific method/methodology: A conclusion will qualify as scientific knowledge if the expert can demonstrate that it is the product of sound “scientific methodology” derived from the scientific method.
The Court defined “scientific methodology” as the process of formulating hypotheses and then conducting experiments to prove or disprove the hypothesis, and provided a set of factors in determining whether these criteria are met:
RULE 702. TESTIMONY BY EXPERT WITNESS
A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:
(a) The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
(b) The testimony is based on sufficient facts or data;
(c) The testimony is the product of reliable principles and methods; and
(d) The expert has reliably applied the principles and methods to the facts of the case.
Expertise in Court cases are subject to the tenets of Daubert and the Rules of Evidence concerning expert witness testimony. ~ Wikipedia.
Matthew Thompson is a Mississippi divorce and child custody attorney and advises that experts can be a valuable tool in the litigation toolbox.