I call the emerging stage Pattern Language 3.0 (PL3.0), distinguishing from the previous stages, which we call here Pattern Language 1.0 (PL1.0) and Pattern Language 2.0 (PL2.0). In what follows, I will presents the evolution of pattern languages and clarifying the difference among these stages.
In what follows, I will explain the evolution of pattern languages from the following three viewpoints: the object of design which pattern languages help, why to make pattern languages, and how to make pattern languages.
The first viewpoint is the object of design which pattern languages help. The object of design with the PL1.0 is physical form like architecture; the object of design with the PL2.0 is non-physical form such as software, interface, and organization; and the object of design with the PL3.0 is form of human action such as learning, collaboration, facilitation, and change agents. The PL3.0 is quite different from others, since the object of design is same to the subject of design only in the PL3.0; there is a self-referential circulation for designing, and accordingly the meta-cognition for designing becomes more important than before.
The second viewpoint is why to make pattern languages. In the PL1.0, a pattern language was used as media for bridging the gap between designers and users: in the case of Alexander’s case, architects and residents; He considered his pattern language helps residents to participate their community development. In the PL2.0, pattern languages were used as media for bridging the gap between expert and non-expert designers: in the case of software design, expert software engineers and non-expert software engineers; It has been common use of pattern languages for software development that non-expert engineers learn the knack of good practice by reading the book. In the PL3.0, a pattern language was used as a media for connecting people who have different experiences: in the case of the Learning Patterns, the workshop are held, where participants talk about their experiences in the light of patterns each other.
The third viewpoint is why to make pattern languages. In the PL1.0, mining and writing of design knowledge are done by expert designers; for example, Alexander made the pattern language in architecture with his fellow architects, and then published as a book. In the PL2.0, collaborative improvement of patterns is introduced: shepherding system and writer’s workshop; while the improvement process is opened, the process of mining and writing is still closed in the expert designers. In the PL3.0, pattern languages are made through collaborative mining, writing, and improvement; finally, all process is opened. Thus, the history of development process of patterns is the history of involving otherness.