The en banc U.S. Court of Appeals for the Ninth Circuit's recent watershed decision in Olean Wholesale Grocery Cooperative Inc. v. Bumble Bee Foods LLC established several significant benchmarks for determining class certification under Rule 23(b)(3) of the Federal Rules of Civil Procedure.

Previously, the Ninth Circuit had not provided clear guidance as to the evidence required to show that common questions predominate over individual inquiries. Nor had the Ninth Circuit addressed whether district courts can certify a class that may contain uninjured members.