The notion of using interaction design patterns in the user experience design process follows the model that computer software programming took when it adopted the concepts and philosophies of Christopher Alexander. Alexander, an architect, wrote the book, A Pattern Language (1977) and A Timeless Way of Building (1979). In his books he describes a language, a set of rules or patterns for design, for how to design and build cities, buildings and other human spaces. The approach is repeatable and works at various levels of scale.