What kind of homework assignments promote learning? We don't need research to confirm that doing homework benefits most (maybe it's all) college students. But there are some vexing issues. If the homework is graded and if those grades count, students will do the homework. But then all that homework must be graded. That can involve a huge time investment for the teacher. So, faculty respond by designing homework assignments that can be graded quickly or aren't graded at all, with students getting credit for completing them, provided the work shows they've made a reasonable effort. Both of those options tend to compromise the amount of learning that results from doing the homework assignment.