The Third Circuit Court of Appeals in reversing the Trial Court’s decision to exclude evidence of a lack of prior claims set forth the test for admissibility. In Moyer v. United Dominion Indus., Inc. 473 F3d 532, plaintiffs, who were factory workers, suffered hand injuries after using a machine used to form metal manufactured by the defendant. The Court of Appeals pointed out that whether evidence of a lack of prior claims is admissible in a diversity case is governed by federal law. And since such evidence may suggest a lack of product defect, lack of an unduly dangerous condition, or lack of causation, it is generally relevant under the Federal Rules of Evidence. The Court held that the District Court erred in excluding the evidence since it was sufficient to satisfy the similarity, breadth and awareness requirements test which it described as follows,
“a) similarity – the defendant must show that the proper testimony relates to substantially identical products used in similar circumstances;
b) breadth – the defendant must provide the court with information concerning the number of prior units sold and the extent of prior use; and
c) awareness – the defendant must show that it would likely have known of prior accidents had they occurred.”