Web & Communication Lab

The C-K theory is a unified Design theory and was first introduced in 2003 (Hatchuel and Weil 2003). The question/challenge being: « is it possible to build a unifed design theory that links design activities in all domains? »

I had the chance to have a presentation of this theory by Philippe  Silberzahn during a course on entrepreneurship and I wanted to go a little bit further on this topic.

The following paper provides a good overview of the foundations of this theory:

http://www.cgs.ensmp.fr/publications/sitearticleconception1/HatchuelWeil2002C-Ktheory.pdf

I especially appreciated this proposition which I believe is at the core of this theory:

« Creating Unknowns from knows: we create unknowns by accepting propositions that do not have a logical status. Then we expand these propositions by giving them new knowledge. But at the same time we create new logical questions that allow us to extend the existing knowledge. »

Here is an attempt to provide my own understanding in 10 points, I apologize in advance towards the authors if I may not have provided a correct transcription of their work…

1 What is design:

we understand first what is design… a very broad definition being « design has been seen as conscious, individual or collective activity » (Alexander 1964).

2 Problem solving:

Moreover, the design is based generally on decision taking theory. « When we study the process of design we discover that design is problem solving » (Herbert Simmon 1995).

3 Traditions:

Different traditions exist for design according the activities:

• architects or artists (and designers)
• Engineers

4 Raisonning versus knowledge

In term of design, we must make a disctinction between raisonning and knowledge.

Of course, both are linked: reasonning allows one to extract from the knowledge to which he has access (the paper takes the example to demonstrate the « convenance des proportions » based on science).

What is a concept versus knowledge in this theory:

• A piece of knowledge is a proposition with a logical status for the designer or the person receiving the design.
• A concept is a notion or proposition without logical status (oblong living room is  neither true, false,  uncertain, undecidable).

5 Notion of expansion

In the artistic area, there is no predefined functions to adress like in Architecture, but rather each artist tries to create new worlds. Be it an imitation of the nature or a freer modern sytle of art.  These new worlds can be interpreted differently by each spectator providing a unique vision.

Expansion is a core notion in any theory of design. Moreover, expansion is a K-relative notion, its significance depends on the knowledge of a designer or any other observer, user: a specialist may see a fantastic innovation in something where we see nothing new.

The capacity of an artist or an architect or an engineer to generate new things is depicted here as expandability. In the case of artists, it is not related to specific reasoning or knowledge.

6 Increasing scientific knowledge

Engineer’s rational on expansion differs from artists and consist in expanding scientific and technical knowledge. Scientifc knowledged can be increased by

• observation,
• experiment,
• calculation,
• modelling

Engineers must be able to consider innovation or imitation of that past at the same time. In the case where there are no ready-made solutions at the beginning of the process, the design activity has to elaborate them.

7 Defining processes in existing theories

Collective practices forced engineers to systemize design reasoning, defining the different stages and control processes for the devices made. Introducing specific language for validation: trials, prototype, tests, ect…

German systematics breaks down the design reasonning in 3 steps:

1. identification of functions
2. choice of the conceptual model
3. embodiement (physical bringing into service of the system)

8 What is new with this theory

In the C-K theory

• There are no separate theory of knowledge:  without concepts, no new knowledge is possible, without prior knowledge there are no concepts (no disjunctions)
• Creating Unknowns from knows: we create unknowns by accepting propositions that do not have a logical status. Then we expand these propositions by giving them new knowledge. But at the same time we create new logical questions that allow us to extend the existing knowledge.
• Bounded rationnality and expandable rationnnality: formal framework encompassing problem solving theory

9 What is the process

How does design reasonning starts? By setting the problem to solve this way (C-K disjunction):

• all the terms of this proposition must belong to K propositions
• the proposition must not have a logical status (otherwise it’s K)

How does it ends (C-K conjunction): when all properties of a concept are true in K.

10 Now we need some practice….

Example of what is a « cool party » concept: we assume that we know enough of what is a party, but that the concept of a ccol party requires some design that cannot be solved by applying the branch and bound method (selection amongst a known partition set of elements).

If one state that parties on a boat or dressed are fancy (concept). You can validate in the K space and visit boat that organize parties. We learned there that it would be cheaper to be taken to an island for the party (new concept).

In the end we decid on a cheap amusing and original party in ordinary dress on an island.  Thanks to this method we learnt new things about events, parties and the process can lead to new disjonctions like parties involving fishing competitions.

Let’s now apply this theory in our own space of design. In research for example creating unknows from known is the holy grail and keeping tracks of the raisonning is key.

I strongly beleive that this method can improveour researcher works….