The Enhanced Scrutiny Of Class Definitions Under The Ascertainability Requirement: An Additional Hurdle for Plaintiffs Or An Increased Burden For Defendants?

When a plaintiff seeks certification of a class, the issue of whether the class is "ascertainable" has become an increasingly significant battleground issue in class certification proceedings. While not explicitly set out in Rule 23 of the Federal Rules of Civil Procedure, ascertainability is now widely recognized as an implied prerequisite for class certification. Ascertainability refers to the requirement that the class definition be sufficiently definite so that it is administratively feasible to determine whether a particular person is a member of the proposed class by reference to objective and definite criteria. Recent appellate authority suggest that both plaintiffs and defendants must consider issues relating to the feasibility of identifying class members when addressing a motion for class certification.