In our daily life too often we encounter products that are difficult to use. For example, selecting different options of the washing machine at home, or using the different settings of the photocopy machine at the office. This book postulates that people's knowledge of products' usage is prompted by their experiences in particular contexts. It describes an empirical study that investigates how human experience and the context of products use influence the way people understand everyday products. This study provides greater detail about the differences between designers and users' concepts of a product's usage, and explains the connection between experience, context-of-use and product usability. It demonstrates the relevance of these principles to the initial stages of the design of product usability, and proposes a conceptual tool to make the new knowledge accessible during a design process. By informing designers about specific causal-relationships between experience, context-of- use and product usability, this study hopes to contribute to the design of more usable products.