You may find your students complaining not only about the number of assignments, but also about their nature, as not everyone thinks they are relevant or helpful based on the set learning outcomes. It is essential that students see the value of the work you request from them, if they are to commit to it.
The nature of student assignments in a course may be influenced by disciplinary teaching culture as much as by the study level and learning outcomes. For example, exercises that involve applying knowledge may seem adequate for basic first year courses; giving them a disciplinary touch will enhance students’ motivation to complete them. Problems to solve, projects, case studies and analysing scientific papers may seem more appropriate for the more professional subjects or discipline-related courses or at a more advanced stage of studies. It can be that the more work is related to a professional application, the higher the student investment.
Given that we learn by doing, it is important that students are actively involved in doing exercises and figuring things out for themselves. In general, it is better to assign guided and supervised work in the early stages of a curriculum and to increase your expectations on student autonomy as they progress along the study plan.