Transfer Student Scores provides a way to move assignments from one class to another within your TeacherVUE account. You may want to use this option if you accidentally posted an assignment in the wrong Grade Book class (if you created additional classes) and need to transfer the assignment and marks to a different class. You may also decide mid-year that you want to place all math assignments in a separate class after multiple assignments have been entered in your default Grade Book. Again, this option makes it easy to move assignments and student marks between classes.
Read this document for additional information.