Not sure it's worthwhile to change, but when making comments keep in mind to keep the comment as general and terminology-free as possible. "Grader" is so ambiguous, and is only colloquially a noun - it is a verb in standard English.

A "rating" is a score a student gives to indicate how well they feel they were graded on this problem

^ this is more clear, avoids additional, confusing terminology while explaining the essence of the term.