exercises 11. user support

	EXERCISE 11.7 Which usability principles are especially important in the design of help systems, and why? answer available for tutors only		Other exercises in this chapter ex.11.1 (ans), ex.11.2 (ans), ex.11.3 (ans), ex.11.4 (ans), ex.11.5 (tut), ex.11.6 (tut), ex.11.7 (tut), ex.11.8 (tut), ex.11.9 (tut), ex.11.10 (tut) all exercises for this chapter