Uncommon Defects and Unreliable Methods: U.S. District Court Effectively Applies Daubert to Deny Class Certification

By Evan M. Tager, a Partner in the Washington, DC office of Mayer Brown LLP, with Carl J. Summers, an Associate with Mayer Brown LLP.

In many civil lawsuits, parties introduce expert testimony to help the jury decide questions of negligence or causation. In class actions, expert testimony is also often employed to help the court answer questions under Federal Rule of Civil Procedure 23, such as whether a class is ascertainable or to develop a formula for awarding damages on a class-wide basis. In Kljajic v. Whirlpool Corp., the United States District Court for the Northern District of Illinois (St. Eve, J.) addressed the intersection of Daubert and Rule 23’s commonality and predominance requirements.

Under Rule 23(a), a plaintiff must show that there are questions of law or fact common to the class. And plaintiffs who seek certification under Rule 23(b)(3) must satisfy the more demanding predominance requirement, which looks to whether the common issues in the case are more important than the individualized issues. These two requirements are similar, and expert testimony can shed light on whether a case can be maintained as a class action. Continue reading →