[bread_baker]

If you have adult students, sometimes there are real situations which make it difficult for the students to do homework. These things include job, child care, living in a house with a lot of other people (too noisy and lacking privacy).
I don't assign homework every week. When I do, I try to not give them preparation for a test too; that is too much. I think students are more receptive when you tell them why that assignment is important and what they are going to learn.
My school gets quite a number of students who never got more than a 6th grade education in their native country; we also get some students who never went to school at all in their native country (illiterate in L1). These students are not used to doing homework and are lacking in study skills. It's a good idea to know what the student population is like before planning and assigning homework.