Logical argumentation

The basic research technique of this project is logical argumentation as defined in Groat and Wang (2002), and it is supported by an analysis of selected generative design system prototypes. Logical argumentation can be classified as a qualitative research strategy following Creswell (2003).

According to the Architectural Research Methods (Groat and Wang, 2002) the research strategy of logical argumentation consists in “an ability to give logical order to a set of previously disparate factors (…) to frame logical conceptual systems that, once framed, interconnect previously unknown or unappreciated factors in relevant ways” (Groat and Wang, 2002: 301-302) .

The authors present a diagram, which illustrates different kinds of systems based on logical argumentation. On the one end of the diagram there are formal-mathematical systems, on the other end there are systems which address cultural issues. The formal-mathematical systems are ready to be digitally implemented (shape-grammar is given here as an example), while the culture oriented systems aim at conceptualising a worldview by displaying it in a logically consistent, systematic and clarified way (the

authors propose the term treatise to denote them and give Vitruvius’s Ten Books of Architecture as an example). Finally, between the two extremes, there are systems combining formal-mathematical and cultural-discursive properties. These systems use equations and principle-based analyses to cast light on social-cultural values. The authors provide Bill Hillier’s and Julienne Hanson’s The Social Logic of Space as an example, where an abstract map and a set of numerical figures are used as an analytic tool to display correspondence between social behaviour and space adjacencies. According to this diagram, my research is positioned between the poles, as it is neither a pure formal-mathematical system ready to be applied in a computer, nor a direct cultural discourse, but features both elements. On the one hand this thesis attempts to address the full spectrum of architectural design, i.e. both quantitative and qualitative aspects, on the other hand it attempts to organise them systematically, to make them applicable to the computational

processing.

Logical argumentation is recognizable by a number of traits. The first trait is a broad explanatory applicability – “[the thesis] tends to have as a research outcome the framing of a conceptual system that has wide explanatory applicability” (Groat and Wang, 2002: 308). Here, the broad explanatory applicability can be understood on two levels.

On the first level, it can be referred to as the research outcome. The principles of the generative design system are meant to be universal - the field of its application is not limited to architecture, but (slightly modified) can be expanded to address design problems in general. Because of the use of Evolutionary Computing, the software would be open to effortless

modification and further development. In addition, the way the software would be used is open. Because the problems the system deals with are

‘wicked’, it can be used as a design problem solver, a design optimisation tool, or a design exploration assistant. Alternatively, the forms it would generate may be used as a source of inspiration.

On the second level, the discussions undertaken here can be applied beyond the CAAD domain. The recognition of a formal structure of a building model appeals to a general systems theory. In this context, a building model is identified with a system and a design process is recognized as a process of adaptation, where a building model adapts to a given building environment (design requirements and design intentions). The analogy between a design process and a process of adaptation elaborated throughout section VIII, can find its application outside the software development activity. In other words, the research contributes to a broader body of knowledge about an architectural design process. In this light, the research findings can contribute to a more informed design practice.

Paradigmatic innovation is another trait of logical argumentation.

Paradigmatic innovation connects disparate factors into novel, unified frameworks that “have significant and sometimes novel explanatory power”

(Groat and Wang, 2002: 309). The contribution of this research is that it brings together heterogeneous aspects of architectural design and proposes a consistent framework for organising and processing them. The aspects (grouped in social, economic and ecological requirements) are recognised and gathered with the help of a ‘characteristics diagram’. The proposal of interrelating, evaluating and finally processing them mathematically is studied in this thesis in the perspective of Evolutionary Computing.

The next trait of logical argumentation is a priori argumentation. A priori argumentation takes place when “any specific instance of a thing is only ratification of principles that the logical system in question has already identified as the enabling conditions for that thing” (Groat and Wang, 2002:

309). The research findings are presented as a set of normative principles for a generative design system. They can be considered as a theoretical basis for the realisation of a generative design system. In other words, any specific instance of a generative design system can be seen as a kind of ‘ratification’

of these principles. Specifically in section IX, the principles are used for critical investigation of the prototypes of the generative design system. The investigation undertaken identifies the limitations of these prototypes.

The last trait of logical argumentation is its testability – the possibility to evaluate the validity or reliability of the theory. In the case of this research, whose aim is to formulate the design system principles, the theory testability must correspond to the testability of the formulated principles. As mentioned in the previous paragraph about research reliability, the principles are to a certain extent testable through professional review by practitioners and academics. The professional skills and academic experience can assess how the projected digital tool can possibly facilitate a design process in its conceptual phases. It is important to emphasise here that the validity of a qualitative research should not be evaluated in terms of its conformity to a set of methods. It is rather “a status given by a reader who is convinced that the research made responsible judgements and exercised care in the production of the study” (Polkinghorne, 2006: 76).