Amendments to Federal Rules of Evidence point out erroneous application of Rule 702 and clarify standards for admissibility of expert testimony


testimony; court; courthouse; expert; testify

By: Kevin M. Ringel and Kevin G. Kenneally

On December 1, 2023, amendments to the Federal Rules of Evidence will take effect to clarify the standard for admission of expert testimony.  The Advisory Committee on Evidence Rules determined amendments to Rule 702 were necessary to make clear the standard for admissible expert testimony is a preponderance of the evidence standard for all four elements of the test, and to emphasize the trial court’s essential gatekeeping role in ensuring the expert’s opinion reflects a reliable application of the principles and methods to the facts of the case.   

The amendments to Rule 702 are below, with new language bold and underlined (and deleted language struck through): 

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 the proponent demonstrates to the court that it is more likely than not that: 

(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 appliedexpert’s opinion reflects a reliable application ofthe principles and methods to the facts of the case. 

The amendments are not intended to bring about a sea change in federal practice.  In discussing the reason for including the added language, the advisory committee explained, “many courts have held that the critical questions of the sufficiency of an expert’s basis, and the application of the expert’s methodology, are questions of weight and not admissibility.  These rulings are an incorrect application of Rules 702 and 104(a).”  Comm. on Rules of Prac. of Proc., Agenda, 891-96 (June 7, 2022) (emphases added) (  

Rather, these inquiries are essential determinations the court must address as threshold questions of admissibility. It is improper for the trial judge to allow a jury to determine the weight they choose to give the disputed expert evidence.  Explaining further, The Committee concluded that emphasizing the preponderance standard in Rule 702 specifically was made necessary because trial judges “failed to apply correctly the reliability requirements of that rule.”  Id.  When seeking to exclude expert testimony, once the court has determined it is more likely than not that the requirements of Rule 702 as to admissibility have been met, any subsequent attack on an expert will go only to the weight of the evidence.   

With regards to Rule 702(d), the Advisory Committee explained that its intention was to emphasize that each expert opinion must stay within the bounds of what can be concluded from a reliable application of the expert’s basis and methodology.  Id. Judicial gatekeeping is essential in determining these bounds, because just as jurors may be unable to meaningfully evaluate the reliability of scientific methods underlying expert opinion, jurors may also lack the specialized knowledge to determine whether the conclusions of an expert go beyond what the expert’s basis and methodology may reliably support.  Id.  With this underscoring of the judicial gatekeeping role, litigants may expect trial courts to undertake a heightened examination of an expert’s proffered testimony before it is presented to the jury.   

While the revised version of Rule 702 is only intended to correct the previous improper application of the rule, anyone introducing or challenging the admissibility of expert testimony must be mindful that prior reported federal cases previously applied an incorrect standard and should be avoided.  Further, expert witnesses must demonstrate their testimony was reached through reliable principles and methods to pass muster under the judicial gatekeeping standard in Rule 702(d).   

The amendments make clear that the rule is rephrased only to reinforce that the rule was not being applied as originally intended, so litigants may cite the revised language immediately, even before the effective date. 

For more information, please contact Kevin Ringel ( or Kevin Kenneally (