Litigators preparing to qualify or challenge an expert witness must be ready to navigate several obstacles in admitting or excluding expert testimony. With the new amendment to Federal Rule of Evidence 702 coming into effect, litigators should take note of changes and incorporate them into their decision-making regarding expert testimony.
In the November 22, 2023 edition of The Legal Intelligencer, Edward Kang wrote, “Battle of the Experts (Standards): ‘Frye,’ ‘Daubert’ and Federal Rule of Evidence 702.”
Expert witnesses can aid jurors in understanding complex issues, and they often significantly impact the success or failure of a case. Litigators preparing to qualify or challenge an expert witness must be ready to navigate several obstacles in admitting or excluding expert testimony. With the new amendment to Federal Rule of Evidence 702 coming into effect, litigators should take note of changes and incorporate them into their decision-making regarding expert testimony.
‘Frye,’ ‘Daubert’ and Federal Rule of Evidence 702
Federal Rule of Evidence 702 controls who can testify as an expert witness in federal court and how these experts are qualified. FRE 702 affects the admissibility, not merely the weight of the evidence. Before Daubert, courts followed the Frye standard, under which scientific evidence could be admitted only if it had enjoyed “general acceptance” in the relevant scientific community. See Frye v. United States, 293 F. 1013 (D.C. Cir. 1923). The Supreme Court’s Daubert decision shifted some of the responsibility for evaluating the reliability of an expert’s testimony to the trial judge, charging them with acting as “gatekeepers” to exclude unreliable expert testimony from the courtroom. See Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993).
Daubert held that federal courts applying Federal Rule of Evidence 702 should consider a nonexhaustive list of five factors in assessing the reliability of expert testimony, including error rate and the existence of standards. It also includes the one factor deemed all-important by the Frye standard—the “general acceptance” factor. Courts engaging in a Daubert analysis apply these factors flexibly.
Pennsylvania courts continue to use the Frye “general acceptance” standard to determine the admissibility of expert testimony. Under the Frye standard, courts analyze whether the methodology used by the expert is generally accepted by the relevant scientific community. This test does not analyze or specify the weight to be given to specific testimony but instead focuses on the scientific validity of the underlying methodology. See Cummins v. Rosa, 846 A.2d 148 (Pa. Super. 2004). Under Pennsylvania’s Frye analysis, the trial court still has a role in assessing the admissibility of expert testimony. Although the trial court may not substitute its own evaluation in finding whether an expert’s methodology is generally accepted in the relevant field, it may rely on the experts and materials offered by the parties. See Walsh v. BASF, 234 A.3d 446, 457 (Pa. 2020).
The Distinction Between ‘Frye’ and ‘Daubert’
The Murray case well illustrates the distinction between the Frye and Daubert standards. In Murray, the court held a four-week evidentiary hearing on the plaintiff’s expert witness testimony, ultimately holding that some of the expert testimony would be admissible under the Frye standard. See Murray v. Motorola, 2014 WL 5817891 (D.C. Super. Aug. 8, 2014). Under the Daubert standard, however, most of the expert testimony would likely have been excluded. Comparing the two standards and the outcomes, the court concluded that if a “reliable, but not yet generally accepted, methodology” produces “good science,” the Daubert standard will let it in. If an “accepted methodology” produces “bad science,” the Daubert standard will keep it out. In contrast, under the Frye standard, even if a new methodology produces “good science,” the testimony will usually be excluded. On the other hand, even if an accepted methodology produces “bad science,” the testimony will likely be admitted. The court thus certified a question for the District of Columbia Court of Appeals as to whether it should adopt the Daubert standard for the admissibility of expert evidence. Through the appeal, the District of Columbia, which created the Frye standard, determined that it should move from the Frye standard to the Daubert standard. See Motorola v. Murray, 147 A.3d 751 (D.C. 2016).
Using the ‘Daubert’ and ‘Frye’ Standards in Practice
It is a common misconception that it is easier for parties to introduce expert testimony under the Daubert standard than the Frye standard. The Daubert standard, however, allows more latitude to challenge and test an opponent’s expert testimony, leading to a significant increase in the number of pretrial motions to exclude such evidence. The Frye standard merely asks the trial court to determine if the methodology used by an expert is “generally accepted.” Thus, the consensus of the expert community is determinative. In contrast, under the Daubert standard, trial judges must assess the methodology and reasoning behind an expert’s opinions and consider the five Daubert factors to determine whether the expert’s methodology is valid. Cases continue to demonstrate the wide latitude that the Daubert standard affords trial judges in ruling on the admissibility of expert testimony, even on subjects accepted before as valid grounds for expert opinion. See e.g., Almeciga v. Center for Investigative Reporting, 185 F. Supp. 3d 401 (S.D.N.Y. 2016) (finding that expert testimony in handwriting analysis was inadmissible because its methodologies were not sufficiently scientifically reliable under Daubert, despite handwriting analysis having been a generally accepted area of expertise in the past).
Key Changes in the 2023 Amendments to Federal Rule of Evidence 702
On Dec. 1, 2023, amendments to Federal Rule of Evidence 702 will take effect. The current Rule 702 states:
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.
The amended Rule 702 will read as follows:
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’s opinion reflects a reliable application of the principles and methods to the facts of the case.
Notably, there are two key changes in the amendments. First, the amendments clarify that an expert’s qualification is based on the preponderance of the evidence standard, meaning that the proponent bears the burden of demonstrating to the court that the proffered testimony is more likely than not to meet the Rule 702 admissibility requirements. The committee note to proposed amendment to Rule 702 explains that the amendment is necessary because many courts have followed an “incorrect application” of the rule. Critical questions of the “sufficiency of an expert’s basis, and the application of the expert’s methodology,” should be threshold questions of admissibility, not the weight of the evidence. As the committee note explains, “once the court has found it more likely than not that the admissibility requirement has been met, any attack by the opponent will go only to the weight of the evidence.”
Second, the amendments also emphasize the role of judicial gatekeeping, that the court is empowered to determine whether the expert’s opinion is “within the bounds of what can be concluded from a reliable application of the expert’s basis and methodology.” The committee note discusses the change as it explicitly allows the court to pass judgment on the conclusion that the expert has drawn from the methodology. The amendment also makes the rule consistent with General Electric v. Joiner, 522 U.S. 136 (1997). In General Electric, the court determined that “conclusions and methodology are not entirely distinct from one another.” As such, the court found that the trial court did not abuse its discretion when it excluded expert testimony because there was an analytical gap between the data and the opinion proffered. The court further held that a trial court must consider not only the expert’s methodology but also the expert’s conclusion, reasoning that not only the methodology need to be reliable, it must be reliably applied for the expert to reach his opinion.
The committee note emphasizes that judicial gatekeeping is “essential” because jurors may lack the specialized knowledge to evaluate and determine the reliability of scientific and other methods underlying the expert’s opinions and whether an expert’s conclusions go beyond what the expert’s basis and methodology might reliably support. While the amendment does not impose new procedures or require a court to “nitpick an expert’s opinion to reach a perfect expression,” it does not permit an expert to make claims that are “unsupported by the expert’s basis and methodology.”
The Daubert standard governs at the federal level and in many state courts. In Pennsylvania, the Frye standard still prevails. Compared to the Frye standard, the Daubert standard allows a party more latitude to challenge and test an opponent’s expert testimony. While the fundamental rule remains largely unchanged, the amendments to FRE 702 offer greater clarity on the criteria federal courts should use to evaluate the qualifications of expert witnesses. Practitioners should avoid citing precedents that will become less persuasive following the amendments. In addition, when preparing expert witnesses, practitioners should ensure they are prepared to defend both the principles and methods they used, demonstrating their relevance and reliability in the specific case.
Edward T. Kang is the managing member of Kang Haggerty. He devotes the majority of his practice to business litigation and other litigation involving business entities. Contact him at firstname.lastname@example.org.