Ever since getting to University (2nd year Mechatronic Engineering now), i find my grades.. or performance in exams/assessments to have fallen since high school. Upon closer inspection, I'm starting to think I just don't put enough time into studying. The course I do features about 23 hours worth of lectures/tutorials/labs during a working week, and roughly 6 hours of assigned 'homework' a week. I find myself doing the bare minimum (or less if i can finish earlier) of this, and not actually committing any time to simply sit down and 'take a subject in' with no goal (eg meeting a due date.) So I'm wondering for a something like Engineering how much time should i be devoting weekly to independent study?