This work gives a broad introductory overview of the topic of usability. Firstly, usability is defined and a framework for identifying different aspects of usability is given. The main principles for creating usable designs are expounded, followed by practical advice as to how to design usable products. The book then tackles the issue of usability evaluation - a series of evaluation methods are described, followed by practical advice as to how to conduct the evaluation. The book draws on examples from software design and product design generally. This means whilst human-computer interaction HCI is a central issue in the book, other usability issues are also covered.