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Five Ways to Survive a Daubert Challenge against Your Expert

Plaintiff’s attorneys frequently battle Daubert motions to strike the testimony of our experts.

By Matthew A. Dolman and Julia N. McGrath.

When the crux of your case centers on your expert’s opinion, the thought of facing a Daubert motion to strike your expert’s testimony may send chills down your spine. As such, it is vital that you keep your strategy for surviving a Daubert challenge at the forefront of your mind as you embark down the path of litigation.

By employing these five techniques, plaintiff lawyers can defeat these challenges and assure that their experts will be able to testify:

  • Highlight your expert’s qualifications
  • Conduct a thorough review of all authoritative literature
  • Illustrate the reliability of your expert’s testimony
  • Be mindful of timing.
  • Be able to educate the judge.


The admissibility of expert testimony


Florida aligned itself in July, 2013, with the majority of jurisdictions that have adopted the United States Supreme Court’s seminal decision in Daubert vs. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), as the standard that governs the admissibility of expert testimony.

A minority of jurisdictions still follow the older Frye standard—a standard that only applies to expert testimony based on “new or novel scientific” principles of procedures: Washington, California, Illinois, Pennsylvania, New York, New Jersey, and Maryland.

The Frye standard


Under Frye, expert testimony is admissible if the principles and procedures are sufficiently established to have gained general acceptance in the particular field for which it belongs. Essentially the trial judge must determine whether the testimony is relevant. i.e., whether the testimony assists the jury in understanding the evidence or determining a fact in issue.

When evaluating expert testimony under Frye and whether the testimony has been “generally accepted” within the relevant scientific community, trial courts have always concerned themselves more with the quality and quantity of the evidence supporting the principles and procedures that the expert bases his/her testimony on, rather than mere general acceptance.

Under Frye, however, if a proponent of expert testimony arms the trial judge with enough information to provide an understanding of what the scientific community believes and accepts, the judge has the ability to then defer to the opinions of the scientific community and allow the testimony.

The Daubert standard


The Daubert standard allows the court to act as a “gatekeeper” of expert testimony and play a more active role in shaping the admissibility of trial testimony. The gatekeeping function is intended to ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable. In Daubert, the Court held that the subject of an expert's testimony must be founded upon "scientific knowledge" and that this requirement established a "standard of evidentiary reliability." Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 590 (1993). The Court further explained that the "scientific knowledge" requirement means that the expert's opinion must be more than subjective belief or mere speculation.

The Daubert opinion articulated four factors to consider when determining the admissibility of expert testimony:

  • Whether the theory can and has been tested.
  • Whether it has been subject to peer review.
  • The known or expected rate of error.
  • Whether the theory or methodology employed is generally accepted in the relevant scientific community.


Under Daubert and its progeny, scientific expert testimony is admissible when the testimony meets the following three part test, according to Kannankeril v. Terminix Int'l Inc., 128 F.3d 802, 806 (3d Cir. 1997).

  • The proffered witness must be an expert. i.e., the witness must be qualified.
  • The expert must testify about matters requiring scientific, technical or specialized knowledge.
  • The expert’s testimony must assist the trier of fact.


The second requirement has been explained to mean that an “expert’s testimony is admissible so long as the process or technique the expert used in formulating the opinion is reliable.” The Eleventh Circuit has referred to these three separate inquiries as determinations of an expert’s testimony’s “qualification, reliability, and helpfulness.”  United States v. Frazier, 387 F.3d 1244, 1260 (11th Cir. 2004).

Responding to a Daubert Challenge


Plaintiff’s attorneys frequently battle Daubert motions to strike the testimony of our experts. One of the reasons is simple: large defense firms know that retaining experts in any case is expense. Factoring in the time an expert may charge for the mere preparation of a report, discovery deposition, and a Daubert hearing, and it becomes readily apparent that the financial stakes are high.

Moreover, when a plaintiff retains an expert to opine about causation or proof of the standard of care and that expert is excluded from testifying based on a Daubert motion, a defense victory by way of a motion for summary judgment is nearly certain to follow.

Daubert-proofing your expert


Thoroughly preparing both your expert and yourself is crucial to survive a Daubert challenge.

1. Highlight your expert’s qualifications


Of course, your expert must be considered qualified to serve as an expert witness to render the opinion that he/she gives. Attaching a detailed curriculum vitae (CV) illustrating your expert’s qualifications in terms of education, training and experience is necessary. Moreover, all published peer-reviewed literature that your expert has written on the subjects for which your expert will testify should be noted.

An expert’s ability to proffer peer-reviewed articles as authority to support his/her opinions weighs heavily on a judge’s determination to grant or deny a Daubert motion. The Daubert court stated that "'peer review'" is significant because ‘scrutiny of the scientific community is a component of "good science," in part because it increases the likelihood that substantive flaws in methodology will be detected.'"

It is also important to point out in your opposition to a Daubert motion that although the court is tasked with performing a gatekeeping function, the court must not consider the persuasive value of the expert testimony. Weighing the credibility of the expert falls within the province of the jury as the fact finder. You should be prepared to argue that if your expert meets the liberal minimum qualification requirement, then “the level of the expert’s expertise goes to credibility and weight, not admissibility.” Kannankeril, 128 F.3d 802 at 809.

2. Conduct a thorough review of all authoritative literature


Taking time to carefully review all of the texts that your expert has published will assist you not only in being able to articulate the reliability of your expert’s testimony, but will allow you the opportunity to spot any inconsistencies in your expert’s opinion in your case and what your expert may have opined in the past. Your expert’s peer-reviewed literature should also provide you with ample material to cross-examine your opponent’s expert on.

Does the Lack of peer-reviewed literature automatically exclude your expert? No. Case law makes clear that the peer-reviewed literature component of the reliability prong is critical. But does the fact that your expert’s opinion is unsupported by peer-reviewed literature mean his testimony will be excluded? Not necessarily. Take Primiano v. Cook, 598 F.3d 558 (9th Cir. 2010).

In Primiano, the plaintiff fell on her kitchen floor and required elbow surgery. During the surgery, her doctor replaced her elbow joint with a device consisting of titanium pieces and polyethylene components made by the defendant. In the eight months following, the plaintiff had to undergo five additional surgeries as a result of ongoing issues the plaintiff was having with her elbow. The plaintiff then filed a products liability claim against the manufacturer alleging the polyethylene components had failed.

To support her theory, the plaintiff called an expert witness to testify that the polyethylene bushing wearing down in less than 8 months was not a usual or expected circumstance because such a device typically last 8-20 years.

The defense filed a Daubert motion to exclude the doctor’s testimony arguing that the expert did not see or examine the plaintiff and there was no peer reviewed literature or publication that the expert relied upon as an objective source for his opinion.

The expert even conceded on cross that there was, “no published peer-reviewed article that [I’m] aware of that states a strict minimum lifespan of a polyethylene component in a total elbow system,” but explained that “I wouldn’t expect any literature, because you don’t see it. It’s hard to write a paper about something that doesn’t occur. I mean, this is really bizarre.”

The trial court excluded the expert’s testimony under Daubert and granted summary judgment.

The 9th Circuit reversed. The court noted that the fact that the expert never treated the plaintiff and failed to produce supporting publications might be useful to impeach his testimony, but did not provide an adequate basis for excluding his opinion. The court acknowledged that lack of peer-reviewed literature is not the death knell for expert testimony, especially in an instance when the expert explained that the phenomenon was so extraordinary that specialists who publish articles do not see it in their practice.

Primiano makes clear that a trial court must consider the totality of the circumstances when ruling on a Daubert motion. If you find yourself pursuing a case that hinges on expert testimony lacking supporting publications, make sure your expert can clearly articulate why such literature is lacking and have the Primiano decision in your arsenal.

3. Illustrate the reliability of your expert’s testimony


The cornerstone of Daubert is being able to demonstrate that your expert’s opinion is derived from sufficient data, utilizes reliable principles and methodologies and can be reproduced by independent testing. If another expert cannot replicate your expert’s analysis, you are unlikely to survive a Daubert challenge. The significance of this cannot be overstated and is not limited to opinions on causation in toxic tort cases.

In Lock Realty Corp v. U.S. Health, United States District Court, N.D. Indiana, South Bend Division, `September 14, 2009, 2009 WL 297033080, for example, the court excluded the plaintiff’s expert from testifying in a breach of contract claim. The expert’s opinion regarding the value of the property was based merely on two emails between the parties and a Medicaid valuation of fair market value. The court took issue with the expert’s lack of relevant source data by which another expert could replicate her analysis. Without doing so, the expert failed to provide reason to think that her approach produces an accurate estimate using professional methods because her method could not be tested

4. Be Mindful of Timing


Of course, your experts should never form an opinion and draft a report before they research all existing authoritative literature. Failure to do so will allow a defendant to successfully move to disqualify your expert under Daubert. Surprisingly, this can happen and courts have acknowledged that “an expert who has formed an opinion before he begins research may be less objective than he needs to be in order to produce reliable scientific results.” Perry v. US, 755 F.2d 888, 892 (11th Cir. 1985).

If possible, finding an expert who has developed his opinion outside of the context of litigation and not expressly for the purpose of testifying will also aid in demonstrating the reliability of the testimony and opinions.

5. Be able to educate the judge


It may be beneficial to have your expert testify live at a Daubert hearing when the testimony relates to a complicated causation issue or will otherwise be unfamiliar to the judge. Some judges may play a more active role in attempting to discern the scientific basis behind your expert’s opinions, while others simply want to make a ruling and move on with the case. Both scenarios require you to be able to demonstrate why your expert’s testimony passes muster under Daubert.

Ultimately, your expert will have to play the role of teacher and must be able to explain and cite the basis to support each step in his/her analysis. Failure to do so may leave an analytic gap that is too attenuated for the judge to accept under Daubert. Remember that not only will this be helpful to survive a Daubert challenge, but it is also critical in successfully presenting your case to the jury.

Final thoughts


As attorneys, we retain experts because they play an integral role in our theory of the case. We depend on our experts. They often hold the key to the testimony required to prove liability, causation and damages. But experts can only offer compelling testimony if given the opportunity.

It is therefore our job to ensure that our expert gets to take the witness stand at trial, look the jurors in the eye, and give the opinions necessary to prevail on our claim. To do that, we must seek out experts who are qualified, whose theories can be tested, and who are willing to put in the same time and effort we are in conducting thorough, unbiased, and objective research before rending a written report.

Our clients deserve it, we strive for it, and Daubert demands it.


att A. Dolman is a member of The National Trial Lawyers top 100 trial lawyers. He and Julia N. McGrath are attorneys practicing at the Dolman Law Group in Clearwater and Bradenton, FL. Matthew is a member of The National Trial Lawyers. He has extensive experience handling first- and third-party insurance claims of all types and, more specifically, claims in the following injury areas: automobile accidents, wrongful death, catastrophic injury, spinal cord injuries, brain injuries, plus violations of Florida’s Consumer Collection Practices Act and asset protection for Florida physicians.

Julia practices in the areas of personal injury, trucking and motorcycle accidents, traumatic brain injury, wrongful death and insurance carrier bad faith.

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