Hi Alpha: Most schools precribe a present curriculum to follow, with variations in how much academic freedom an instructor has in adjusting their course to meet the objectives. Student centered teachers will want to grasp where the cumulative core of their students are at and put more emphasis on those areas where the need exists, and where the students would benefit most. Of course, the course objectives have to be met, but there are many ways to achieve that, and it's great when the instruction is reaching the students rather than presenting just our preplanned methods. Regards, Barry