The modern era of class action litigation began with the 1966 amendment of Rule 23. Rule 23 thereafter provided that courts should determine “[a]s soon as practicable” whether a class “is to be so maintained.” Although the rule set forth explicit criteria for class certification, it made no mention of the procedures or standards by which a court should determine whether a class action was appropriate, did not note a specific time when proponents must seek certification or when a court must issue a certification decision, did not require courts to conduct class certification hearings, and did not indicate what burdens of proof, if any, the parties to class litigation bear on class issues.
Not surprisingly, in the years that followed, courts entertained class certification motions on an ad hoc basis. Throughout the 1980s and early 1990s, courts willingly certified class actions based on the plaintiffs’ pleadings alone; indeed, some defaulted to a presumption favoring class certification. See, e.g., Linda S. Mullenix, “Abandoning the Federal Class Action Ship: Is There Smoother Sailing for Class Actions in Gulf Waters?,” 74 Tul. L. Rev. 1709, 1715 (2000). Even so, the word “ascertainable”—a buzzword today—appeared frequently enough in case law for authors Charles Alan Wright and Arthur Miller to note in their first edition of Federal Practice and Procedure that although “the class does not have to be so ascertainable that every potential member can be identified at the commencement of the action, . . . the general outlines of the membership of the class must be determinable at the outset of the litigation.” 7 C. Wright & A. Miller, Federal Practice and Procedure § 1760, at 580 (1972).