Carol,
I try to relate as much of my class content and policies to the world of work. EC is not part of most peoples job. So I choose not to give EC assignments. I will allow student to work on additional assignments for "learning value", but these have no impact on grading whatsoever. It's usually the stronger students who engage in these activities anyway (the ones who don't need EC). I want to focus on learning rather than points and grades. Beccuase I've had too many problems in the past with questions of fairness (by students), conistency in grading, grade inflation, and entitlement or reliance on EC to "earn" certain grades (at the expense of other required course assisnments), I simply choose not give EC, and make that clear on day-1 of class. Each teacher and institution has to decide what works best for their classes. This is my bias, and because students know it, they don't ask for grade adjust EC assignments (because they know what the answer will be). Makes teacher-life a little bit less stressful!
Barry Westling