Sharon Russell (plaintiff) began a nursing program at Salve Regina College (College) (defendant) in 1982. Due to the College’s concern that Russell’s obesity would interfere with her ability to complete the nursing program, Russell signed a contract with the College in which she agreed to lose weight in order to continue in the nursing program. Russell failed to meet the requirements of the contract and withdrew from the program. Russell subsequently sued the College, alleging a breach of its implied agreement to educate her. The College moved for a directed verdict. The United States District Court for the District of Rhode Island denied the motion on the grounds that there was a factual issue as to whether Russell had substantially performed under her agreement with the College. The College renewed its motion after trial. The College argued that the doctrine of substantial performance did not apply in the academic context and that, since Russell had admitted she had not fulfilled all the terms of the contract, the College was entitled to judgment as a matter of law. The district court denied the motion. The district court determined that although the doctrine of substantial performance had previously been limited to construction contracts, the Supreme Court of Rhode Island would extend the doctrine of substantial performance to Russell’s case. The district court judge based his conclusion on his prior experience as a Rhode Island state court trial judge. The jury was instructed to apply the doctrine of substantial performance. The jury found in favor of Russell, and the College appealed. The United States Court of Appeals for the First Circuit affirmed, finding that it was required to defer to interpretations of state law made by district court judges sitting in that state. The College petitioned for certiorari, and the United States Supreme Court granted certiorari.