A rating scheme is a schema
It is a schedule that is used to evaluate something or someone. It helps the person who is judging to see if they have appointed all aspects and have not forgotten anything. For example, the schema may require a certain amount to be done by someone, or something must be done within a certain time. By using the schema, everyone is judged in the same way and there is no difference in the result. It is often referred to as a rating matrix or a rating template.