Recently, Attali and Powers investigated the usefulness of providing immediate feedback on the correctness of answers to constructed response questions and the opportunity to revise incorrect answers. This article introduces an item response theory (IRT) model for scoring revised responses to questions when several attempts are allowed. The model is based on Samejima's graded response model, where the graded responses are defined as the number of attempts needed until a correct answer is given, and the response with the least credit is awarded for an incorrect answer after the maximum number of attempts has been reached. Advantages of this conceptualization are discussed and empirical results are presented. (Contains 2 tables and 1 figure.)