Homework should not be additional work
Research has not shown that assigned homework offers any benefits. In fact, in some schools, assigning homework is discouraged.
So how should we treat homework?
We should treat it as a deadline. When you are employed, you have deadlines and you need to complete the work by a specific time. As a teacher, I assign work and give it a due date, whether it is at end of class or the next day. If a student completes that work, that student should work on assignments from other classes, read independently or work on something else. This gives the student practice on making important decisions while using time wisely.
Every student works at a different pace. If a student finishes early, that student is showing good time management. If a student does not finish by the end of class, the student is either not using time wisely or is struggling with the assignment.
Differentiation is about working with the struggling students, so the teacher can utilize his or her resources and focus on the students who need additional instruction along with a flexible due date. Fairness is giving people what they need.
Speaking of differentiation, we need to separate activity FROM accomplishment. If a student is not accomplishing anything, it is meaningless to add more activity just to make the teacher, the school or the district look good.
If a student is wasting time, then that student should go home and finish the assignment and submit it by the next class session.