Is designing hermeneutical?1 It is commonly supposed that design activity can

be described, codified and explained in terms of an algorithmic logic model

derived from language theory. The model, exemplified in the work of Stiny,

Knight, Mitchell, Kalay and Coyne et al., has been the basis of much research

in architectural design methodology and CAD.2 Mitchell gives an elegant

description of the model.3 With reference to nineteenth-century formal-

pictorial positivism, and the twentieth-century logical positivism of Carnap,

he asserts that design can be described in words that make up a critical

language and such word descriptions can be formalised using the notation of

first-order predicate calculus. Design worlds, he says, consist of ‘graphic

tokens which, like words, can be manipulated according to certain

grammatical rules’. He sees design processes ‘as computations in design

worlds with the objective of satisfying predicates of form and function stated

in a critical language’.4 Mitchell specifies that there are three main parts to

this model:

First … the relationship of criticism to design may be understood

as a matter of truth-functional semantics of a critical language in

a design world. Second … design worlds may be specified by

formal grammars. Third … the rules of such grammars encode

knowledge of how to put together buildings that function

adequately. Thus the relation of form to function is strongly

mediated by the syntactic and semantic rules under which a

designer operates.5