Since I teach a computer class, I can walk around and see the kids working every day. Sometimes, when something is due, students will lose their work, claimed it got deleted, claim it is saved at home, etc.
I have always given my students a %50 on an assignement they "lost." I know they worked on it, cause I can see them working on it every day. However, that doesn't mean they finished it, and they couldn't turn it in when it was due.
If the project is worth 20 points, they get a 10. That way, the missed assignment doesn't destroy their grade, and they can recover from it.
As for trying to get students to turn in their homework who do not? If you can figure that out, please share with me.
You really have to take into consideration all of the variables.
I've worked at several different elementary and middle schools in my career. At most of them, there were always one or two students who almost NEVER completed homework. No matter what was done -- calls home, punishment, reflection journals, etc. -- they didn't do it.
Then, I worked at a KIPP middle school. The demographics of the school were similar to the others where I worked -- low-income, minority students. But one of the mottos of the school was "No shortcuts, no excuses." As a school, we set up a culture of high expectations and academic success. Students learned that homework was a large part of their success.
Because the staff knew how important homework was to the structure of the next day's lesson, we agreed on a zero-tolerance policy for homework. Every morning, homeroom teachers checked every student's homework for every subject (thus eliminating the time used for this in content classes). If anything wasn't finished -- even if they just didn't write their name at the top of the page -- it was considered 'incomplete.' If any single assignment was missing (or only half done), homework was considered 'missing.'
Incomplete homework meant a mandatory lunch detention, where students ate in silence but could NOT work on their homework. Missing meant a mandatory after-school detention, where students completed reflection packets, answering questions about why they were there, how that behavior impacted them and their teammates, and how they could fix it.
Incomplete or missing homework was then due the following day. Within a few weeks, we went from 50% of kids not finishing homework to one single student who was consistently missing an assignment. This in a school where kids were in class from 7:30 a.m. to 5 p.m. and had an average of 2 hours of homework per night.
Here's why I think it worked:
I agree with Doug "They may just see it as a waste of time. In many cases they are not wrong", and had a similar discussion with my mom yesterday. We were talking about me trying to take a tour of the elementary school my son will go to in the fall of 12 (he's 3 now). I asserted that I would be evaluating how instruction is handled as well as homework, and technology. I have never really put too much stake in repetitive homework that's just there for the sake of doing it. After watching Race to Nowhere I am ready to fight if need be to reduce the homework of my children, as long as they can show they understand the material.
I am also making changes to how I address homework in my classes. I will have certain assignments that are for skill building and not evaluated, and some evaluation assignments. For the assignments that are evaluated I am going to use scales to assess the completeness of the work as well as the learning objectives (Blog post). I am still working on how I will include all of this into and end of the semester grade, I have a felling almost the entire grade will be from an expanded portfolio and practical exams at the end.
I really believe that repetitive homework that is force to be done after the student understands material is detrimental. It just make them loose interest in the subject, with adversely affects how well they learn future material. I believe that is why I dislike math as much as I do.The things I understand I can do well, but doing something I didn't understand 50 times didn't help me learn it any better, and made me resent the entire subject.
As far as homework credit, I put as much grade emphasis on completing assignments as I do on completing them well. Of course you want both, but struggling students won't get buried with low scores. Not completing an assignment on time for me would depend if it happened continuously. I normally give a grace period of one day. If this happened all the time or if a student never completed assignments, then you need to try to find out why. It may be that the parent is part of the problem by having the kid work after school or scheduled too many extracurricular activities. You'll be able to tell a lot from how the student reacts (i.e. oops, I don't care, embarrassment, etc.)
Keep a record of your notifications to parents or administrators on the issue. Using email is an easy way to accomplish this. You don't want anybody saying they weren't informed in the future or end up in a heated parent-teacher conference.
You should talk to the student and find out what the problem might be. They could be experiencing problems at home. They may not understand the material. There are many different issues that could be going on, so I think the best thing to do would be to talk to the student and try to understand what the source of the problem is and go from there.