Participation is difficult to achieve in some cases. As stated, some do not see the need.....no payoff! Often I suspect this attitude is reflected in their daily lives, so getting them to buy into your class requirements is tough! Tough even when not doing homework or lessons has a negative effect on their grade! I do try the "write a short paper on why I'm here" or "what do I expect to learn" exercise, and sometimes it works. My best success comes when I can help them see the possibility of a positive outcome and how their unique situation can improve.