External Properties: the User’s Perspective
Christian Gram, Gilbert Cockton · 1996
The usability of an interactive system is linked to the quality of the dialog, and quality shall here be expressed through a number of measurable properties of the dialog. The aim of this chapter is to identify and define a set of user-centered properties of interactive systems which promote high quality from the perspective of the users. The set must be as complete and mutually independent (‘orthogonal’) as possible. At the same time these so-called external properties must be usable in the software development process as yard-sticks or ‘measures’ in the quality plan for the development. For a particular system, some of the properties may be absolute requirements (this interactive system must have such and such property), while others are desired in a quality plan but are given some ‘weight of importance’ (0 ≤ ω < 1). Once we understand these properties and their implications, and also the internal properties presented in the next chapter, we will be able to discuss how to construct interactive systems possessing desired and required properties. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.