Friday, July 22, 2011

Pattern Language 3.0

Recently, I'm thinking about the methodological evolution of pattern languages, which is a method to describe design knowledge in a certain domain from the viewpoint of problem finding and problem solving (Alexander, 1979). 

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.

Saturday, July 2, 2011

A Brief Summary of the History of Systems Theory

In the current academic context, there are several theories under the name of "systems theory". In this post, I shall overview a history of the systems theory. We adopt, here, a categorization suggested by Hideo Kawamoto (1995), where the development of the systems theory is divided into three generation (See the Table below).

First generation is summarized as the theories for dynamic equilibrium systems, and their key concept is "homeostatis". They focused on the mechanism how a system maintains itself under the fluctuation from the environment. Leading scholars in this generation are Walter Bradford Cannon of "homeostasis" (Cannon 1932), Ludwig von Bertalanffy of "general systems theory" (Bertalanffy 1968), Norbert Wiener and W. Ross Ashby of "cybernetics" (Wiener 1948; Ashby 1956). The sociologist who applies this generation theory is Talcott Parsons as "social systems theory" (Parsons 1951).

Second generation is the theories for dynamic nonequilibrium systems, and their key concept is "self-organization". They focused on the mechanism how a structure of system is crystallized from disorders. Leading scholars in this generation are Ilya Prigogine of "dissipative structure" (Prigogine & Nicolis 1977), Manfred Eigen of "hypercycle" (Eigen & Schuster 1979), and Hermann Haken of "synergetics" (Haken 1977).

Third generation is the theories for self-production system, and their key concept is "autopoiesis". They focused on the mechanism how a system itself is realized over time. Autopoietic system means a unity whose organization is defined by a particular network of production processes of elements. Leading scholars in this generation are Humberto Maturana and Francisco Varela of "autopoiesis" (Maturana & Varela 1972, 1980; Varela & Maturana, 1974). The sociologist who applies this generation theory is Niklas Luhmann as "social systems theory" (Luhmann 1984).

Note that there is a clear distinction between "self-organization" and "autopoiesis" after the revolution caused by third generation. In this context, self-organization is focused on structural formation, but autopoiesis is focused on system formation. Luhmann emphasizes this distinction as follows:

"Autopoietic systems, then, are not only self-organizing systems, they not only produce and eventually change their own structures; their self-reference applies to the production of other components as well. This is the decisive conceptual innovation. […] Thus, everything that is used as a unit by the system is produced as a unit by the system itself. This applies to elements, processes, boundaries, and other structures and, last but not least, to the unity of the system itself." (Luhmann 1990: p.3)
"In order to clarify how much this concept of basal self-reference differs from an earlier discussion of "self-organization", Maturana and Varela have proposed the designation `autopoiesis’ for it." (Luhmann 1984: p.34).

As just quoted, the difference between "self-organization" and "autopoiesis" is of decisive importance for understanding the conceptual innovation of the systems theory.

Ashby W. R. (1956). Introduction to Cybernetics, Methuen.
Bertalanffy, L. v. (1968). General System Theory: Foundations, Development, Applications, George Braziller
Cannon, W. B. (1932). The Wisdom of the Body, W. W. Norton.
Eigen M. & Schuster P.(1979) The Hypercycle: A principle of natural self-organization, Springer
Haken, H. (1977). Synagetics, An Introduction. Nonequilibrium Phase-Transitions and Self-Organization in Physics, Chemistry and Biology, Springer.
Kawamoto, H. (1995) Autopoiesis: The Third Generation System (in Japanese), Seido-sha Publishers.
Luhmann, N. (1984). Soziale Systeme: GrundriƟ einer allgemeinen Theorie, Suhrkamp. (English translation: Social Systems, John Bednarz Jr., Dirk Baecker (translator), Stanford University Press, 1995)
Luhmann, N. (1990). Essays on Self-Reference, Columbia University Press.
Maturana, H. R. & Varela, F. J. (1972). De Maquinas y Seres Vivos, Editorial Universitaria S.A.
Maturana, H. R. & Varela, F. J. (1980). Autopoiesis and Cognition: The realization of The Living, D. Reidel Publishing Company.
Parsons, T. (1951). The Social System, Free Press.
Prigogine, I. & Nicolis, G. (1977). Self-Organization in Non-Equilibrium Systems, Wiley.
Varela, F.J., Maturana, H.R. & Uribe, R. (1974). "Autopoiesis: the organization of living systems, its characterization and a model", Biosystems, Vol.5, No.4, pp.187-196.
Wiener, N. (1948; 1965). Cybernetics: Or Control and Communication in the Animal and the Machine, 2nd edition, MIT Press.