In this dissertation
I will endeavour to evaluate the wide ranging concept of usability
in the development and design of interactive systems in a methodical,
concise and readable way. Despite each chapter relating to a separate
topic, I will demonstrate that topics are often interrelated,
intrinsically affected by one another and how, in combination,
they influence the overall design of an interactive system.
As cited by Preece et al
 it is unfortunate that "information in books has to
be presented sequentially". This is especially apparent when
dealing with the subject of usability since it is composed of
a wide ranging but inextricable and associated set of topics.
In order to present this information in a more representative
way, which truly reflects the nature of the concept, this dissertation
contains many internal references. Indeed this piece, ideally,
could have been written in a hypertext format.
2, I will initially discuss what usability actually is and
how, if possible, it can be measured. Then, in the subsequent
chapters as a general theme, I will demonstrate how usability
is interpreted and to what extent it is considered in respect
to the development and design of interactive systems.
3, I will describe the relatively recent increase in awareness
of usability issues, why this has happened and the possible consequences
if system usability is relegated to a low design priority.
4, 5 & 6
I will evaluate, in detail, the various concepts within the topics
of feedback, guessability, and user centred design. By illustrating
with real examples, I will establish links between the theoretical
and real worlds in order to assess the merits and weaknesses of
relevant theories, notions and models.
7 is a report on how user centred design is applied in practice
in industry. My case study gives an account of the usability methodology
used at Reuters, which not only involves their "customer
centred design process" [RUG 1997] but also, incorporates
their usability testing arrangements.
Finally, I conclude with chapter