By Kelly J. Wilbur, Esq.

Expert witnesses may be retained to assist in the certification process for a class action lawsuit. These assignments are typically extremely lucrative. The lawyers will usually be willing to pay for top quality work-which takes time.

Such assignments are also extremely high stakes. Whether or not a class can be certified can determine if litigation is pursued at all. For this reason, expert witnesses who work on class certification assignments can expect to be rigorously challenged. Such challenges include qualifications, Daubert, and all the requirements of Federal Rule of Evidence 702.

Class actions are governed by Federal Rule of Civil Procedure 23.  In order to be certified as a class, the plaintiffs must show, among other things that: 1) the class is so numerous that trying the cases separately would be impracticable (numerosity); and 2) there are questions of law or fact in common (commonality).  Expert witnesses can be asked to assist on both of these issues during the class certification process. For example, an engineer in a product liability case could be asked to opine that a defect affected all products the same way and that numerous products were affected.

Expert witnesses who work on class action certification may be asked to write reports, be subject to discovery such as expert witness depositions regarding class action certification, testify as an expert witness at a class action certification hearing, and be subject to Daubert and other challenges.

There will typically be millions of dollars at stake in each certification decision.  This means that the expert testimony regarding class certification is critically important. The lawyers involved will be expected to vigorously challenge all such testimony. Expert witnesses who are engaged to assist in the class action certification process should be well-trained and prepared and strive to produce the highest quality work product.

About the Author

Kelly J. Wilbur, Esq., is a Trainer and Consultant for SEAK, Inc – The Expert Witness Training Company. She was an insurance defense and commercial litigator for five years prior to joining SEAK. Kelly received her J.D., cum laude, from the University of Massachusetts School of Law in 2015 and graduated from St. Mary’s College of Maryland with a B.A. in Political Science. While at St. Mary’s, Kelly was a member of the nationally ranked varsity sailing team and was a two-time All American. Kelly has taught, trained, and consulted with hundreds of expert witnesses and is the co-author of SEAK’s 2021 Survey of Expert Witness Fees. Direct Dial:  781-491-6802 Email: