Class CertificationIn cases that involve large numbers of plaintiffs and similar allegations, many attorneys attempt to certify multiple plaintiffs as a group or “class,” and in so doing, the litigation is consolidated and handled in a more uniform manner than if each case were tried individually. Expert witnesses play a vital role in helping a court determine the class certification in such cases and therefore, whether myriad lawsuits should proceed as a class action.


Class certification has important implications. As one legal analyst explains, “If granted, a plaintiff’s individual claims can be transformed into claims asserted on behalf of hundreds or thousands, subjecting a defendant to substantial additional exposure. On the other hand, if class certification is denied, it can be the death knell of the litigation, as the reduced stakes no longer justify investment by the named plaintiffs or their counsel.” M. Joseph Winebrenner, “Expert Evidence at Class Certification and the Role of Daubert,” American Bar Association, Jul. 16, 2015. Because class certification can be such a critical issue, it is common for savvy litigators to “invest in expert evidence to support, or oppose, a class-certification bid.” Id.

The Federal Rules of Civil Procedure (FRCP) govern the determination of whether or not a group of individuals should be certified as a class. Specifically, FRCP 23(a) “requires the proponent of class certification to prove four elements: (1) numerosity—that the class is so numerous that joinder of all members is impractical; (2) commonality—that there are questions of law or fact common to the class; (3) typicality—that the claims or defenses of the representative parties are typical of the claims or defenses of the class; and (4) adequacy—that the representative parties will fairly and adequately protect the interests of the class.” Id. Additional requirements for class certification are discussed in FRCP 23(b), which concerns the type of class action that an attorney seeks. See id. Finally, the proponent of class certification must “propose a class definition in terms that are objectively identifiable—a final requirement known as ascertainability.” Id.

 In order to achieve class certification, plaintiffs’ attorneys must do more than simply draw up pleadings requesting such a status.  Instead, the United States Supreme Court has held that parties seeking class certification must “be prepared to prove” that the requirements of FRCP 23 are met. Wal-Mart Stores, Inc. v. Dukes, 131 S. Ct. 2541 (2011). The Court made clear that class certification is only proper if, after it imposes a “rigorous analysis,” the trial court feels that the FRCP 23(a) prerequisites are satisfied. Id. The Court’s “rigorous analysis” standard has been interpreted to impose a strict requirement on those seeking class certification, and the resulting tests imposed by trial court judges are often addressed by expert witnesses. As one commentator argues, “Given these strict requirements, parties both supporting and opposing class certification often rely on—and challenge—expert evidence at the class-certification stage. Given the Supreme Court’s directive that district courts must perform a “rigorous analysis” of proof, the precise role of the Daubert inquiry, as part of the “rigorous analysis,” has become a recurring focus of motion practice in district and circuit courts.” M. Joseph Winebrenner, supra.

There is a split among the federal circuit courts as to whether or not a full Daubert-style hearing is required during the class certification determinations. See id. However, regardless of whether or not the federal courts require a full-scale Daubert hearing to decide if a case should proceed as a class action, each circuit has acknowledged that some sort of focused inquiry is necessary to make a class determination. See id. Accordingly, regardless of the exact standard that a particular circuit applies, attorneys in federal court should be prepared to offer qualified expert testimony in support of their arguments. Furthermore, although the circuits have differed in terms of the extent that a Daubert inquiry should apply in matters of class certification, “most courts—including the Supreme Court—recognize that Daubert plays some role.” Id. Some circuits have expressly argued that credible expert testimony is a prerequisite to class certification, and have held that such testimony must meet Daubert or Daubert-like standards in order for a court to grant a class certification motion. See id.


Regardless of the type of “rigorous analysis” a federal court chooses to apply, two things are clear. First, whether attorneys support or oppose class certification, each side should have competent expert witnesses available to argue the matter. Second, attorneys should be aware that the trial courts will impose strict requirements on expert evidence. Accordingly, litigators should prepare their experts to be held to some form of Daubert-style scrutiny in class certification matters. Given how important the granting or denial of a class certification motion is for both sides, expert witnesses who can withstand rigorous tests from courts and opposing counsel may play an invaluable role in the success or failure of such motions.


By: Kat S. Hatziavramidis, Attorney-at-Law