Working With Experts: Understanding the Five Daubert Factors


Five Daubert Factors“In this case, we are called upon to determine the standard for admitting expert scientific testimony in a federal trial.” So begins Daubert v. Merrell Dow Pharmaceuticals, Inc., a Supreme Court case that changed the landscape of expert witness testimony and case preparation when it was decided in 1993.

While originally aimed at scientific methodologies and the expert witnesses who employed them, Daubert and its five-factor evaluation have since been expanded to experts in non-scientific domains as well. The five Daubert factors are applied in federal courts and in a number of state courts.

Today, nearly every litigation attorney who relies on an expert witness is familiar with the Daubert factors. Many witnesses, however, are unfamiliar with them. Keeping the Daubert factors in mind during witness depositions and trial preparation can do much to ensure that the witness’s testimony is admissible and admitted at trial.  

Daubert v. Merrell Dow Pharmaceuticals: A Refresher

After Jason Daubert and Eric Schuller were born with serious birth defects, their parents sued Merrell Dow in a California state court, claiming the birth defects were linked to Benedictin, a drug produced by Merrell Dow. Both the plaintiffs and the defendant called in multiple expert witnesses to present their respective sides of the debate: Did Benedictin cause the boys’ birth defects or not?

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The trial court granted summary judgment to Merrell Dow, finding that the testimony of the plaintiffs’ experts was inadmissible because it was not based on scientific principles “sufficiently established to have general acceptance in the field to which it belongs.”

The Supreme Court disagreed. Instead, the Court noted that the controlling standard was not “general acceptance,” but the standard set forth in the Federal Rule of Evidence 702, which states that a qualified expert witness may testify in the form of opinion or otherwise if:

  1. The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or determine a fact in issue,
  2. The testimony is based on sufficient facts or data,
  3. The testimony is the product of reliable principles and methods,
  4. The expert has reliably applied the principles and methods to the facts of the case, and
  5. In some federal courts, a Daubert challenge must occur regarding any review of an expert.

Managing the Daubert Factors With Your Expert Witness

A Daubert challenge may be the deciding factor in whether or not your expert’s testimony, in the form of opinion or otherwise, can be admitted at trial. Keeping the Daubert factors in mind at the start can help you choose an expert witness who can weather the challenge.

Start with thorough background research on your expert witness. Delve into past publications, academic degrees, licenses and certifications, any past deposition or trial transcripts, records from any previous Daubert challenges the expert has weathered, and a full background check. A copy of the expert’s CV can give you a convenient list of academic and professional work from which to operate.

If you already know which experts your opponent is likely to retain, perform similar background research on these experts. Talk to your prospective expert witness about them. Your expert may be able to suggest strategies for a challenge or ways to address opposing experts’ methodology or conclusions in court.

Finally, discussing the basics of Daubert motions and challenges with your expert witness can prove invaluable. By providing your expert with some background before a challenge ever occurs, you can gain your expert’s perspective on their field and the ways in which knowledge and authority are developed and demonstrated in that field. This information, in turn, can help you more successfully address a potential challenge.

About The Author

Dani Alexis Ryskamp, J.D., is a freelance writer and legal book critic with experience practicing insurance defense, personal injury, medical malpractice law, and criminal defense.

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