In my class, students have access to all of the answers in the problem sets.  I post them in the front of the room every day.

Students no longer have an incentive to copy answers from their neighbor or from the back of the book.  These answers are available the same day the assignment is given and stay posted for 24-48 hours.  I believe that providing answers free of charge eliminates any incentive to copy them from a friend or the back of the book as well as provides instant right/wrong feedback.  I always thought it was strange when math teachers would hide (it took me four years to work up the guts and break "tradition" in this area of my professional career) the answers until the next day - if I was doing something wrong, I would want to know sooner rather than later, so why wouldn't my students desire the same timely feedback?  I regularly encourage students to check their answers during and outside of class and come in for extra help if they have more than three unrelated and unresolved questions.  I'll go ahead and admit that students don't regularly come in outside of class for extra help, but that may be a direct result of the support they're provided between bells.  Here's the way it works:

At the beginning of class each day, students check any remaining answers and write the numbers of the problems they still do not understand on the board (just to the right of the posted problems).  I like this system for two reasons.
  1. It gives me a quick idea of the ideas students are still struggling to understand.
  2. Anonymous marks are the norm.  No single student stands out in the crowd for being the "dumb" one.
It did not take long to realize this is an imperfect system.  Time does not allow to go over every single problem students don't understand.  If only a few students wish to go over #15, is it worth the entire class' time to discuss it?  Time is a realistic factor that comes into play each and every day.  Students don't always have time to come in outside of class for help and we don't legitimately have time during class to answer all of their questions either.  What is the solution?

At the beginning of the year, I amended the process described above by adding one more step.  After I've finished answering several of the questions from the board and before students hand their papers in, I ask them to write one of the following words that best describes their current understanding of the problems: green, yellow or red.  Green means the student has a good idea of what's going on. Yellow means the student is a bit shaky on one or more ideas/problems.  Red means the student is really lost and hopefully plans on coming in outside of class to get extra help.  I also encourage students to write specific questions and/or problem numbers that they still do not understand on their papers.  I regularly vow to them that I will provide written feedback to their questions.  I feel like it's a natural extension of the question answering session at the beginning of class and at least in my mind, makes up for the fact that I can't answer all of the questions students are still unsure about.  A typical yellow paper looks like this:

Student A

Note at the top of the paper that Student A had questions about #s 3, 12, and 20.   Notice also that Student A did not attempt or give me any inclination of his/her misconception.  My notes are in red.  A few questions are running through my head...

Because Student A did not even attempt the problem, am I working harder than him/her by providing the first steps to each of the problems?  Am I encouraging this type of cop out behavior via the green, yellow, red and written feedback system?  Sometimes the system yields great questions with practical feedback as seen in Student B's paper below.

Student B

Is there a better system I could be piloting?  I have tried peer feedback in the place of my all-class remediation at the beginning of class based on the questions students ask.  It usually looks something like, "Who understands #5?  Okay, if you were one of the students that wrote #5 on the board, please see Suzie in a few moments.  Who understands #12? Okay, if you..." It usually works the first time or two, but eventually morphs into social time very quickly because so many high school students aren't mature enough get help from one friend for one problem and then move to another friend who can help with a second or third problem.  Is there an alternative I'm missing?

Does Student A REALLY want help or is he/she just going through the motions to please Mr. Townsley?  After all, if he/she had a strong desire to learn about these concepts, wouldn't he/she have put in more effort intially (a la Student B) and/or come in outside of class to virtually guarantee one-on-one instruction to remedy any misconceptions?  That's admittedly the old school teacher side of me coming out. 

Last, if Rick DuFour is right in saying that learning should be the constant while time and support are the variables, how does this play out in a high school classroom?   How much responsibility for taking the initiative to learn lies on me, the teacher and how much of it lies on the student?  Is it realistic to encourage students to come in outside of class or should my remediation take place solely between bells?
    I'm just not sure how to help students who (sort of) want help.  Tweaks? Overhauling the system?  I'm willing to learn from your experience in the comments section.