Homework Policy - Extension with Partial Solutions for Partial Credit I'm going to be teaching my first course in the fall semester, and I've been trying to think of ways to make the homework benefit the students. One thought I had was to have the homework be due the week following its assignment for full credit, at which point partial solutions would be posted to the course site, or at the following lecture for partial credit. I can think of variants where parts of the assignment could be submitted at each deadline, so if a student figures out how to do problems 1, 3, and 4 but has no idea on problem 2, he can submit the three he figured out for full credit at the first deadline, then use the partial solutions to figure out the last problem and turn it in for partial credit at the second deadline.

What are the benefits and drawbacks for the students and administrators of such a system? Students: Is this a system that you would find helpful? Instructors: Have you tried anything similar in the past, and if so, what were the results?

This is what I've been able to think of so far:


Administrators


(+) Encourages students to look at the solutions
(+) Helps homework be a learning experience
(-) Requires two sets of solutions if full solutions are posted later
(-) Requires more organization, especially if students are allowed to submit on multiple days

Students


(+) Provides an extra resource when working through the assignment
(+) Encourages completion of the assignment, which should increase retention because students are using (some) of the knowledge
(-) Confusing system
(-) Assignments will overlap if assigned weekly
I give weekly assignments and post the full solutions immediately after the assignment is due.  However, I also give partial credit (50%) to any assignments turned in after its due date but before the final exam.  

I have seen a handful of students utilize this system.  Typically they are the ones who normally complete assignments but missed the deadline due to extraneous circumstances.  I consider these use-cases to be exactly in the spirit of my policy.  Occasionally, I will have a student who submits virtually all of the assignments in the last week of the term.  I see this as an unintended consequence of the policy (I would actually prefer to discourage this kind of procrastination).

There are a few downsides from an instructor's point of view:


There is a higher organizational load than if you enforce a strict deadline.  I find the marginal cost of grading a late assignment to be surprisingly high.  If assignments came any more frequently than weekly, I am confident my system would become onerous, and the one you propose would be even worse.
There is a risk that an honest (but poor) on-time effort by a student could be surpassed by a dishonest late effort by another student.  I haven't seen this but it is a worry in the back of my mind.  I try to avoid this by actively encouraging students who do poorly (worse than 50%) to re-submit after looking at the solutions.