The Daubert standard provides a rule of evidence regarding the admissibility of expert witnesses testimony during United States federal legal proceedings.

Pursuant to this standard, a party may raise a Daubert motion, which is a special case of motion in limine raised before or during trial to exclude the presentation of unqualified evidence to the jury. The Daubert trilogy refers to the three United States Supreme Court cases that articulated the Daubert standard:

  •     Daubert v. Merrell Dow Pharmaceuticals, which held in 1993 that Rule 702 of the Federal Rules of Evidence did not incorporate the Frye "general acceptance" test as a basis for assessing the admissibility of scientific expert testimony, but that the rule incorporated a flexible reliability standard instead;
  •     General Electric Co. v. Joiner,[1] which held that a district court judge may exclude expert testimony when there are gaps between the evidence relied on by an expert and his conclusion, and that an abuse-of-discretion standard of review is the proper standard for appellate courts to use in reviewing a trial courts decision of whether it should admit expert testimony;
  •     Kumho Tire Co. v. Carmichael,[2] which held in 1999 that the judges gatekeeping function identified in Daubert applies to all expert testimony, including that which is non-scientific.


Synopsis: In the wake of the U.S. Supreme Courts 1993 Daubert decision, federal court practitioners face an obstacle course of new requirements in qualifying expert witnesses.
I. An Introduction Prior to the adoption of the Federal Rules of Evidence, all federal and most state courts followed the "Frye" test to determine the admissibility of scientific evidence. In Daubert v. Merrell Dow Pharmaceuticals, Inc., the United States Supreme Court held that the Federal Rules of Evidence, and in particular Fed. R. Evid. 702, superseded Fryes "general acceptance" test. Fed. R. Evid. 702 contains two requirements. First, the evidence must be reliable, or in other words, trustworthy. Trustworthiness guarantees that the information is supported by scientific methods and procedures. Second, the evidence must be relevant. The criterion of relevance has been appropriately described as one of "fit."  To satisfy this requirement, the proffered testimony or evidence must be sufficiently tied to the facts of the case that it will help the jury in resolving a factual dispute. "Rule 702s helpfulness standard requires a valid scientific connection to the pertinent inquiry as a precondition to admissibility."
Faced with a proffer of expert scientific evidence, the trial court is charged with the role of "gatekeeper" and must initially determine, pursuant to Fed. R. Evid. 104(a), whether the expert is proposing to testify to scientific knowledge that will assist the trier of fact to understand or determine a fact in issue. This decision demands an evaluation of whether the reasoning or methodology underlying the testimony is scientifically valid and can be applied to the facts at issue.
In Daubert the Supreme Court provided four nondefinitive factors that trial courts should consider in making this determination. First, the court should evaluate whether the theory or technique can be and has been tested. Second, the court must determine whether the theory or technique has been subjected to peer review and publication., Third, the court should consider the known or potential rate of error. Finally, the court should evaluate the general acceptance of the theory in the scientific community. The Seventh Circuit has added an additional consideration: whether the proffered testimony is based upon the experts special skills.
In addition to these four Daubert factors, other safeguards exist to protect against the admission of unreliable or irrelevant scientific evidence. Federal Rules of Evidence 703, 706 and 403 each provide an independent check. Procedures familiar to every trial attorney, such as vigorous cross examination, the presentation of contrary evidence, and careful instruction of the jury on the burden of proof, also help guard against the acceptance of suspect scientific evidence. Finally, the Federal Rules of Civil Procedure prevent cases from going to trial where the evidence is unreliable.

II. Disclosure of Experts Through Rule 16 Scheduling Orders and Judicial Abrogation of Fed.R.Civ.P. 26(b)(4)

A. Drafting the Scheduling Order With Experts In Mind In any lawsuit where experts may testify on an issue, the prudent practitioner should consider including in the Rule 16 scheduling order an in limine Daubert hearing on the admissibility of expert testimony. Since the Supreme Court issued its Daubert opinion, courts have encouraged litigants to request a Fed. R. Evid. 104(a) in limine hearing on the admissibility of proposed expert testimony. The in limine hearing alerts the trial judge to potential disputes concerning experts and requires the court to recognize its obligations under Daubert and Fed. R. Evid. 104(a) to make a preliminary determination concerning the admissibility of proposed expert testimony. Scheduling the Daubert hearing at the outset of litigation reduces the risk of evidentiary ambush arising from the late disclosure or nondisclosure of experts. Of course, the courts role at the Daubert hearing is limited to determining whether the proposed experts testimony is derived from an application of the scientific method and "fits" the issues in the case. The persuasiveness of expert testimony, and the resolution of conflicting expert testimony, remain the province of the trier of fact. 

A pretrial Daubert hearing provides counsel with a preview of the opponents case. In many drug and product cases, the plaintiff may win or lose on the testimony of the plaintiffs experts. If the plaintiffs expert on an essential element of the plaintiffs burden of proof is precluded from testifying, the defendant can and should move for summary judgment. In many cases, defendants move for summary judgment prior to the Daubert hearing so that the trial court can simultaneously consider both the admissibility of the plaintiffs expert testimony and whether any genuine issues of material fact exist for trial.

B. When Should Experts Be Disclosed?

In the absence of other directions from the court or stipulation of the parties, Fed. R. Civ. P. 26(a)(2)(C) requires that experts must be disclosed at least 90 days before trial, and rebuttal experts no later than 30 days thereafter. Based upon the complexity of the issues and the anticipated expert testimony that may be presented by the parties, counsel should attempt to determine as early as possible whether these Rule 26 default deadlines come too late in the case. If, for example, rebuttal experts are not designated until 60 days before trial, opposing counsel is faced with the formidable task of conducting additional discovery, obtaining transcripts of prior depositions on an expedited basis, consulting with counsels own experts, preparing for trial, and preparing for the in limine Daubert hearing. In some jurisdictions, it may be impossible to file timely dispositive pretrial motions given these late disclosure and discovery deadlines.

On the other hand, if experts are designated too early in the lawsuit, the chances are good that their opinions will have to be supplemented as discovery progresses. Nevertheless, from a defense perspective, knowing the identity and number of a plaintiffs experts and the general subject matters on which those experts may testify can provide invaluable assistance in retaining consulting experts, evaluating the case for settlement, and preparing for trial. The simultaneous designation of experts by both plaintiff and defendant should be avoided unless exceptional circumstances justify such a procedure. Simultaneous designation could negatively affect the defendants ability to prepare, especially in a complex case.
One alternative to simultaneous disclosure of all experts on all issues is staggered discovery, in which the case is broken into parts. Factual discovery on certain issues may be cut off at agreed upon times, with the designation of experts to follow shortly thereafter concerning that particular topic. Staggered discovery might be especially attractive where determination of a particular issue would be case dispositive.

C. Which Experts Should Be Disclosed?

Fed. R. Civ. P. 26(b)(4), at least on its face, appears to answer the question of which experts should be disclosed. Experts testifying at trial must be disclosed, while consulting experts retained in anticipation of litigation or in preparation for trial do not have to be disclosed, except upon a showing of exceptional circumstances that it is impracticable to obtain facts or opinions on the same subject by other means. At a Daubert hearing on the admissibility of expert witness opinions, however, the rules of evidence basically do not apply. Accordingly, the trial court may consider not only a broad array of evidence, including offers of proof, affidavits, stipulations, learned treatises, testimony, and documents, but also legal argument. The trial court may also consider testimony presented to other courts addressing the same evidentiary issues, and the opinions of those courts on the same subject. Finally, the trial court may take judicial notice of well established scientific facts or techniques.

Despite the provisions of Fed. R. Civ. P. 26, Daubert and its progeny have upset, if not completely abrogated, the testifying-nontestifying dichotomy envisioned in Rule 26, at least for purposes of the Daubert hearing. Courts can and should require disclosure of all experts whose testimony will be submitted to the trial court, whether at trial or at the Daubert hearing. Yet, because the rules of evidence do not apply to the Daubert hearing, parties arguably may offer at the Daubert hearing testimony of experts who will not testify at trial. To close this loophole, which otherwise might prevent a party from effectively cross-examining an opponents experts on vital issues, the scheduling order should require that all experts whose testimony will be submitted either at trial or in any motion must be disclosed and made available for deposition. In certain cases, the parties may also want to ask the court to order that any experts whose research or data a partys testifying experts may rely on be disclosed and made available for deposition. 

III. Motions for Summary Judgment and the Daubert Hearing

Motions for summary judgment are especially appropriate in connection with the Daubert admissibility hearing. If the court determines that expert testimony is inadmissible, and the proponent of the expert testimony has no other evidence to support one or more of the required elements of its cause of action, summary judgment should be granted. To take advantage of this process, the party moving for summary judgment must adduce facts demonstrating the expert is not qualified to render the opinion, the opinion is not reliable, and the opinion is not relevant. Finally, the moving party must comply with Fed. R. Civ. P. 56(e), which requires "experts to set forth facts and explain the reasoning they used in reaching their conclusions rather than simply providing naked conclusions." 

IV. Medical Evidence Under Daubert

A. Is the Medical Expert Qualified?

Under Fed. R. Evid. 702, the proffered witness must be "qualified as an expert." A treating physician with personal knowledge of the plaintiffs injury and history should be considered an expert. Some courts may also require that the treating physician have an appropriate specialization to diagnose and treat the plaintiffs injury or disease.

B. Is Medical Testimony Reliable?

Various factors will support a finding that medical evidence is reliable. The fact that the proffered expert is the plaintiffs treating physician weighs heavily in favor of reliability. Similarly, proffered expert testimony is considered more reliable when the expert has personally examined the plaintiff and personally reviewed the plaintiffs medical records. To further increase the reliability of the evidence, the expert should take the plaintiffs medical history, perform objective tests, and study peer reviewed literature. An experts employment of standard scientific practice, such as the use of traditional medical assessment technology, ruling out possible alternative causes, performing a differential diagnosis, and developing a working diagnosis, also strengthen the reliability of the experts testimony. It should be noted, however, that even if the expert employs a method that is scientifically reliable, the basis of the experts conclusion must also be reliable. In preparing for trial, the expert should read all of the depositions in the case.
The expert should not form the opinion first, and then go in search of facts to support that opinion. An experts reliance on "anecdotal" evidence as opposed to "empirical" findings decreases the reliability of the evidence, just as an experts reliance on faulty or inaccurate data would diminish the reliability of the experts conclusions. The experts testimony will be particularly suspect when the expert has not conducted any independent research outside of the litigation on the subject matter of the experts testimony. Federal courts have rejected experts who have arrived at testable conclusions, but failed to test those conclusions or subject them to scientific scrutiny. The "hired gun" generic expert who in the past may have been allowed to testify on just about anything will not survive scrutiny under Daubert.

C. Is the Medical Testimony Relevant? Relevance asks whether the proposed expert testimony will assist the trier of fact in deciding a disputed issue. Courts have found that proposed "expert" testimony concerning matters of common sense or common knowledge, or not involving any scientific or technical knowledge, fails the Daubert relevance test. In most cases, the relevance prong of Daubert pertains to what is sometimes called "specific causation." For example, the scientific community may accept the fact that radiation at certain levels over given periods of time causes cancer (general causation). To prove that the plaintiffs cancer was caused by radiation requires proof that the plaintiff was exposed to sufficient amounts of radiation for an adequate period of time (specific causation). Specific causation may also require proof that other factors, such as smoking, did not cause the plaintiffs cancer. A plaintiff in a products liability action must demonstrate that even if the products design was defective and no warning was given of the defect, the defective design or absence of a warning was at least a substantial factor in causing the plaintiffs injury or illness. Proof that certain dosages or concentrations of chemicals cause harm is insufficient to prove that a plaintiffs injury or illness was caused by the chemical in the absence of any evidence that the plaintiff was exposed to the chemical at the required levels.

V. Daubert And Missouri Courts

In 1989 the Missouri legislature adopted § 490.065, which provides in pertinent part:

1. In any civil action, 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. This provision parallels Fed. R. Evid. 702, with the exception of the limitation to civil cases. While several Missouri courts have recognized the potential effect of Dauberts holding on §  490.065, no Missouri court has yet decided whether § 490.065 will be construed in tandem with Daubert. Practitioners in Missouri state courts should object to the admission of expert testimony that does not comport with the requirements of Daubert and §  490.065.

VI. Conclusion

In the aftermath of Daubert, federal courts have taken their role as gatekeepers seriously. Expert testimony that would have easily passed the Frye test for admissibility is being excluded under the more stringent requirements of Fed. R. Evid. 702 as construed by Daubert. Because of the often critical "make-or-break" role that expert testimony plays in many cases, prudence mandates vigilance at all stages of litigation to ensure that proposed expert testimony is subjected to careful scrutiny under the Daubert standards during discovery, in limine, and at trial. Scheduling orders should include a Fed. R. Evid. 104(a) hearing on expert testimony, and should also require the disclosure of all experts whose testimony may be offered, whether at trial or at any pretrial Daubert hearing. Daubert provides opportunities not previously available to exclude "junk science" well before trial if counsel is careful and diligent during the discovery and pretrial phases of a case.