This book illustrates the techniques developed by the usability
engineering for designing accessible and usable artifacts. The author
analyzes some examples of wrong designs whose faulty user interface
was the cause of expensive repairs and in the case of some famous air
crashes, even the lost of life. Crucial techniques such as card
sorting, heuristic evaluation, personas and remote testing are
analized depending upon their use in different development stages. All
of those techniques are employed to increase the accuracy of the user
modeling. These models are used to predict the behavior of users in
different interaction scenarios. As a result, the author proposes a
model-based design architecture, allowing to separate the user
interface into four layers that facilitate their design and
implementation separately.