the daubert standard on websleuths forumsforjustice.org JonBenet

In United States federal law, the Daubert standard is a rule of evidence regarding the admissibility of expert witness testimony.

In Daubert, seven members of the Court agreed on the following guidelines for admitting scientific expert testimony:

   Judge is gatekeeper: Under Rule 702 of the Federal Rules of Evidence, 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". Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 584-587. Concerns about expert testimony cannot be simply referred to the jury as a question of weight. Furthermore, the admissibility of expert testimony is governed by Rule 104(a), not Rule 104(b); thus, 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 proponent can demonstrate that it is the product of sound "scientific methodology" derived from the scientific method.[3]
   Illustrative factors: The Court defined "scientific methodology" as the process of formulating hypotheses and then conducting experiments to prove or falsify the hypothesis, and provided a set of illustrative factors (i.e., not a "test") in determining whether these criteria are met:

   Whether the theory or technique employed by the expert is generally accepted in the scientific community;
   Whether it has been subjected to peer review and publication;
   Whether it can be and has been tested;
   Whether the known or potential rate of error is acceptable; and
   Whether the research was conducted independent of the particular litigation or dependent on an intention to provide the proposed testimony.[4]

In 2000, Rule 702 was amended in an attempt to codify and structure elements embodied in the "Daubert trilogy." The amended rule then read as follows:

   Rule 702. Testimony by Experts

   If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.

(As amended Apr. 17, 2000, eff. Dec. 1, 2000.)

In 2011, Rule 702 was again amended to make the language more clear. The rule now reads:

   RULE 702. TESTIMONY BY EXPERT WITNESSES

   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.