In the realm of class action litigation, Federal Rule of Civil Procedure 23 (Rule 23), and its state equivalents, outline the major requirements for class certification. The explicit requirements of Rule23 therefore frame the classic battle ground for determining whether a law suit qualifies for class treatment.
Often overlooked, however, is a critical, implicit, preliminary requirement for class certification, known as ‘‘ascertainability.’’ In order to satisfy the ascertainability prerequisite, plaintiff must demonstrate the ability to define the putative class interms that make the class members objectively identifiable.
This article describes the ascertainability requirement and explores the three different ways courts have applied it as a basis to deny class certification.