The American Sociological Association (ASA) filed an amicus brief in Wal-Mart v. Dukes in which the ASA defended the testimony of the plaintiffs’ sociological expert. Unfortunately, the ASA’s portrayal and defense of the method and opinions of this expert do not match the actual method used, and opinions offered, by the expert in the Wal-Mart case. The authors demonstrate that none of the ASA’s defenses of the expert’s method has merit and that the expert violated basic methodological rules set out by the ASA’s own sources. The opinions to which the expert testified, therefore, lacked a scientific foundation.