Pattern Languages For Interaction Design

Alexander recorded his observations in a format called "design patterns" which summarize the context of a problem and its solution. For example, one design pattern, "Opening to the Street," is illustrated with a photograph and begins with the essence of the pattern: "The site of action is an incentive for action. When people can see into spaces from the street their world is enlarged and made richer, there is more understanding; and there is the possibility for communication, learning." Notice his description focuses on the human experience. Next is a detailed elaboration of this scenario, including a report of his observations and other architectural references. The pattern continues with a solution: "In any public space which depends for its success on its exposure to the street, open it up, with a fully opening wall which can be thrown wide open, and if it is possible, include some part of the activity on the far side of the pedestrian path, so that it actually straddles the path, and people walk through it as they walk along the path..." He concludes the pattern with a line drawing and a list of related patterns.