The total scaled score will determine whether the candidate passed and is based on the number of questions answered correctly. The ABPTS requires a scaled score of 500 to pass the examination. Scaling is a procedure that converts raw scores (number of correct responses) to a more easily interpretable scale. The reason for calculating scaled scores is that different versions of the exam may vary in difficulty. As new forms of the exam are introduced, a certain number of questions in each content area are replaced by new questions. These changes may cause one version of the exam to be slightly easier or more difficult than another version. The purpose of scaling scores is to simplify things by keeping the passing score at the same number (eg, 500) for all exam forms, while the raw scores necessary for passing may vary for different versions.