Code of Civil Procedure section 382 authorizes class action lawsuits "when the question is one of a common or general interest, of many persons, or when the parties are numerous, and it is impracticable to bring them all before the court . . . ." In order to maintain a class action, certain prerequisites must be met, specifically, "the existence of an ascertainable class and a well-defined community of interest among the class members. The community of interest requirement embodies three factors: (1) predominant common questions of law or fact; (2) class representatives with claims or defenses typical of the class; (3) class representatives who can adequately represent the class." (Richmond v. Dart Industries, Inc. (1981) 29 Cal. 3d 462, 470, 174 Cal. Rptr. 515, 629 P.2d 23.) Moreover, it must be shown that a substantial benefit both to the litigants and to the court will result, and the burden of that showing falls on the plaintiff. (City of San Jose v. Superior Court (1974) 12 Cal. 3d 447, 460, 115 Cal. Rptr. 797, 525 P.2d 701.) A class action cannot be maintained if each individual's right to recovery depends on facts peculiar to that individual. (Id., at p. 459.) An order certifying a class is reviewable for abuse of discretion provided that correct criteria were used. (Osborne v. Subaru of America, Inc. (1988) 198 Cal. App. 3d 646, 654, 243 Cal. Rptr. 815.) If the trial court's decision is based on erroneous legal assumptions or it applied improper criteria we reverse even though there may be substantial evidence to support the court's order. (Richmond v. Dart Industries, Inc., supra, 29 Cal. 3d 462, 470.)