In the view of the M364 module team, HCI has been superseded by ID. This is because HCI traditionally concentrated upon desktop computers with single users, whereas ID includes the theory underpinning, and the practice of, designing the whole array of interactive products which now exist, many of which are used by more than one person at a time.

Usability. Usability is a widely used term, particularly among ID practitioners. For example, there is a large and successful Usability Practitioners Association (UPA). Usability is defined in Part 11 of the ISO 9241 standard as 'the extent to which a product can be used by specified users to achieve specified goalswith effectiveness, efficiency and satisfaction in a specified context of use(British Standards Institution, 1998).

Box on page 14 of the Set Book defines usability engineers as 'people who focus on evaluating products, using usability methods and principles'. So usability engineers spend much of their time evaluating the usability of products.