How to Survive a Daubert Challenge

What is a Daubert Challenge?

A Daubert challenge acquired its name from the seminal Supreme Court decision on which the challenge is based. In Daubert vs Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), the Supreme Court set a new standard for the admissibility of expert testimony, which was codified in Rule 702 of the Federal Rules of Evidence and is followed in federal courts as well as a majority of state jurisdictions. Per Daubert, in addition to considering whether an expert witness’s opinion has been generally accepted in the scientific community (also known as the Frye standard, which was followed for decades prior to Daubert), the Court also enumerated other factors to consider:

1. Whether the expert’s technique or theory can be tested and assessed for reliability
2. Whether the technique or theory has been subject to peer review and publication
3. The known or potential rate of error of the technique or theory
4. The existence and maintenance of standards and controls

When opposing counsel challenges an expert’s opinion under Daubert, typically that involves poking holes in the expert’s qualifications, methods, and the scientific basis of the testimony – not necessarily the conclusion itself. But if an opponent successfully calls into question the techniques on which an expert’s opinion is based, the expert runs the risk of having part or all of their testimony excluded from evidence.

What to Expect During a Daubert Challenge

Because many jurisdictions require the parties to disclose reports that detail their expert’s qualifications as well as their opinions in advance of trial, any objection opposing counsel may make to your witness will likely occur prior to the start of trial (and outside the presence of the jury). In fact, a motion to exclude expert testimony that is raised too close to trial may even be denied by a court for lack of timeliness. A Daubert challenge may happen by written motion, or the court may schedule a hearing which can involve the expert giving testimony as well.

Preparing Your Expert Witness

The best way to prepare your expert witness for a Daubert challenge is to keep in mind the potential of a challenge when first retaining an expert. An expert’s opinions should strive to satisfy the factors enumerated in Daubert, with a focus on their methods and the scientific basis used to reach their conclusions. More generally, it is also useful to choose an expert whose qualifications match the specifics of the case at hand. 

Effective Strategies to Survive a Daubert Challenge

Expert Qualifications Beyond Reproach

An expert is typically deemed qualified during the voir dire process, which occurs at the beginning of direct examination when counsel asks the expert about their occupation, education, training, and other important background information. Although these questions are asked during trial, an expert’s qualifications invariably come up well in advance of trial, such as when their identity is disclosed to opposing counsel. Therefore, it is possible for opposing counsel to attack an expert’s qualifications during a Daubert motion, arguing that the expert is not qualified in the subject matter at hand.

In fact, in one recent study, challenges to an expert’s qualifications were the most successful Daubert motions, with a success rate of 43%. The best way to circumvent this challenge is to ensure your expert possesses all the requisite qualifications required for their position (such as degrees and licensures) and that their background and all relevant history is clearly spelled out in their curriculum vitae.

A Solid Methodology

The pivot from Frye to Daubert was largely based on the notion that an expert’s conclusions are not as important as how those conclusions are reached. Therefore, an expert should be ready to explain their methodologies, which include any testing conducted, the testing’s rate of errors, and the existence of any standards and controls, in reaching their opinions.

Address the Entire Challenge

When defending against a Daubert challenge, you will want to be as thorough as possible, which means addressing any and all arguments made against your expert. This may involve addressing all of the applicable Daubert factors individually and defending against each one, such as whether the expert’s opinion has been peer-reviewed and generally accepted by their respective scientific community.

An expert should be prepared with documentary evidence to support their opinions, especially in cases where the science is not as clear-cut. If the opinion is not entirely supported by the scientific community yet – in the case of competing methodologies or novel sciences – the expert will need to explain why.

Stay Within the Scope of the Case

If an expert has a broad array of knowledge in their respective field, it can be tempting to opine on general issues or topics. But for the purposes of Daubert, an expert should focus on the specific issues at hand, which may involve staying within a sub-specialty. The expert’s opinion should be narrowly tailored to the issues and the issues should be directly related to the expert’s specific expertise, as opposed to their generalized knowledge.

Know Your Audience: Be Mindful of the Judge’s History

Judges dislike frivolous motions, and poorly timed Daubert challenges can backfire. Researching the judge’s past rulings and tailoring your arguments to their decisions can demonstrate respect and efficiency. Present written materials and testimony clearly and concisely, acknowledging that judges may be unfamiliar with the expert's field. Throughout the Daubert process, aim to establish the relevancy and reliability of your expert’s testimony.

What Happens Next?

If you successfully survive a Daubert challenge, you are one step closer to being able to admit your expert’s opinion into evidence at trial. That being said, it is important to remember a Daubert challenge may be opinion-specific, meaning that, if your expert alters their opinion, or changes their underlying methodology, it is possible that their opinion may be challenged again.

Likewise, if you lose a Daubert challenge, all may not be lost. Although your expert’s testimony will be excluded at trial, there may be a chance to rectify the situation depending upon the court’s basis for the exclusion. Depending on the specifics of the court’s reasoning, it may be possible to move for a reconsideration of the motion, this time presenting evidence that could counter the reasons that the court found your expert’s opinion inadmissible.

Case Studies

For example, in the Johnson & Johnson baby talcum powder multidistrict litigation, the court previously denied the defendant’s Daubert motion back in 2020, allowing five of the plaintiff’s general causation experts to testify in upcoming bellwether trials to establish that the powder causes ovarian cancer. But with trial delays over the course of the past four years, as well as a Rule 702 amendment and developing scientific literature on the topic, the new judge that took over the MDL docket has ordered a new round of briefing on expert evidence, signifying a chance for J&J to successfully challenge plaintiff’s experts (and successfully defend their own).

In contrast, a recent decision by the Federal Circuit illustrates how a successful Daubert motion can withstand appellate scrutiny. In the patent infringement case, EcoFactor, Inc. v. Google LLC, the plaintiff alleged that Google’s Nest smart thermostat products infringed on its patent for a thermostat system that collects temperature readings and makes future predictions. After Google’s Daubert motion to exclude the plaintiff’s damages expert was denied, the expert showed that prior license agreements were economically comparable to a hypothetically negotiated agreement between the parties. The jury found in favor of EcoFactor’s patent and awarded damages. On appeal, the Federal Circuit upheld the trial court’s Daubert ruling, finding that the expert correctly used a proposed royalty rate from three license agreements the plaintiff had with manufacturers to calculate the reasonableness of such rates.

How to Avoid a Daubert Challenge in the First Place

Although you cannot control if and when opposing counsel chooses to challenge your expert, the best way to avoid a Daubert challenge altogether is to retain the right expert for your case. At Expert Institute, we deliver the leading expert candidates based on your case-specific criteria and vet all experts in our network. It is critical to research an expert beforehand, which we handle for you with Expert Radar. With the use of AI, we find all of an expert's publications, licenses, certifications, previous litigation activity, and prior Daubert challenges.

Generally, there is a 40-50% chance that a Daubert motion may be successful, resulting in the complete or partial exclusion of expert testimony and a potentially damaging trial outcome. It is critical to focus on your expert’s qualifications and their relevance to the specific issues or sub-specialties present in the case. An expert’s methodologies, and whether they have been reliably tested, is a key factor, but it is also important to keep in mind the other Daubert factors as well. Overall, by developing an offensive strategy before a challenge is even made, and then attacking the individual points of each challenge that is raised against your expert, will ensure a successful outcome.