Each instructor has preferences relating to which classes they are most qualified or most willing to teach and during which time periods and days they would prefer to teach. These preferences can be accessed by the administrator who has the authority to edit the preferences, as necessary to help generate schedules that are overall more fair to all instructors. When the administrator changes preferences, the instructor's personal preferences are not changed in the database, only a copy of them used in the generation of a schedule is modified. To see the steps taken for an administrator to edit preferences check out Section 2.3.1.4.2 . Each instructor can edit his/her preferences, which changes their overall preferences for every quarter after that. To see the steps taking for an instructor to edit preferences check out Section 2.3.1.4.1 .