When talking about standards-based grading, I often hear the argument...

I agree with the standards-based grading philosophy, but I'm nervous about not grading homework and other practice assignments.  How do you motivate students to complete homework (or other non-graded assignments)?
My responses:
  1. What do you do with students in the traditional system who don't do homework even when it is graded? 
  2. Does the student need to complete the homework/practice assignment?  If he/she already understands the big ideas, doing the homework probably is not a good use of time. 
  3. Engage in a conversation with your students that looks something like this...
    Teacher: "If homework was worth 3 points, how many of you would do it?"
    (Many hands go up)
    Teacher: "Okay, if homework was worth 2 points, how many of you would do it?"
    (Still lots of hands go up)
    Teacher: "If homework was worth 1 point per day, how many of you would do it?"
    (Several hands go up)
    Teacher: "If homework was not graded, how many of you would do it?"
    (A few hands go up)
    Teacher: "Johnny, why would you still do your homework?"
    Johnny: "My parents would still make me do it."
    Teacher: "Thanks for your honesty, Johnny.  Suzy, why would you still do your homework if it was worth zero points?"
    Suzy: "I love math class!"
    Teacher: "I do, too, Suzy.  Thanks for your enthusiasm.  Frank, why wouldn't you do your homework if it wasn't graded?"
    Frank: "If it's not graded, it would give me more time to play Playstation with my friends." 
    Teacher: "Frank, if you didn't do your homework for this unit, how well do you think you'd do on the test?"
    Frank: "I would probably fail the test or get a D."
    Teacher: "Thanks for your honesty, Frank.  If you didn't do your homework again for the next unit, how well do you think you'd do on the test?"
    Frank: "I would probably fail or get a D again." 
    Teacher: "Frank, how many tests do you think you'd have to fail before you realized that doing your homework is a good idea?" 
    Frank: "Probably two or three."
    Teacher: "Okay, now that you know that...why wouldn't you just do your homework?"
At one time in my teaching career, I "hid behind points."  Rather than having a discussion like the one above with students, I took the easy way out by giving students who didn't complete their homework a zero in the grade book.  My students didn't benefit.  It was the easy way out for them, too.  Confronting the reality that homework/practice/formative assignments and activities are important opportunities for feedback [not merely point accumulation exercises] is a classroom shift that requires ongoing discussion with students.  How do you accomplish this in your classroom?