In adjudicating benefits claims under the Black Lung Benefits Act (BLBA) and the Longshore and Harbor Workers' Compensation Act (LHWCA) D applies what it calls the 'true doubt' rule. This rule essentially shifts the burden of persuasion to the party opposing the benefits claim -- when the evidence is evenly balanced, the benefits claimant wins. This is a review of two separate decisions of the Court of Appeals for the Third Circuit. In one, Andrew Ondecko (P) applied for disability benefits under the BLBA after working as a coal miner for 31 years. The Administrative Law Judge (ALJ) determined that Ondecko (P) had pneumoconiosis (or black lung disease), that he was totally disabled by the disease, and that the disease resulted from coal mine employment. In resolving the first two issues, the ALJ relied on the true doubt rule. In resolving the third, she relied on the rebuttable presumption that a miner with pneumoconiosis who worked in the mines for at least 10 years developed the disease because of his employment. The Court of Appeals vacated the Board's decision, holding that the true doubt rule is inconsistent with the Department's own regulations under the BLBA. Michael Santoro (P) suffered a work-related back and neck injury while employed by respondent Maher Terminals. Within a few months, Santoro (P) was diagnosed with nerve cancer, and he died shortly thereafter. His widow filed a claim under the LHWCA alleging that the work injury had rendered her husband disabled and caused his death. After reviewing the evidence for both sides, the ALJ found it equally probative and, relying on the true doubt rule, awarded benefits to Santoro (P). The Board affirmed, and the Court of Appeals reversed, holding that the true doubt rule is inconsistent with § 7(c) of the APA. The Supreme Court granted certiorari.