For over 20 years, organisations have been making use of information technologies to enable global distribution of products and services through the World Wide Web. This move to digital business has resulted in the need to consider usability from a global perspective, and in particular, the effects of cultural differences on user performance. Despite the large number of studies done in this area, many of the websites currently available are still difficult to understand and complicated to use. Consequently, this book proposes a conceptual model of usability that provides a more effective tool for continued research into the complex issues of usability and cultural diversity. The model is a synthesis of primary research findings and existing context of use frameworks, and includes new aspects concerning culture. Variables that need to be controlled for are identified, as well as strategies for controlling for these variables. For practitioners, the model can be used to provide a better understanding of the design and user experience goals that should be incorporated to make websites easier and more enjoyable to use, by matching them more closely to user needs and expectations.