Dear Jurgen and all,

For testing theory, I've found Popper's 'three incommensurate worlds' model useful (Popper 1976).
It gives some clear and precise boundaries and insights.

Most people think of 'falsification' as the mainstay of Popper. His 'Three Incommensurate Worlds' model is what locates that understanding about the role of  falsification, and provides the real value of Popper's work  in understanding 'testing' and the devising of tests for validity.

Put simply, Popper argues reality can be separated into three incommensurate worlds:

	1. The world of subjective  and subjective experiences

	2. The world of theory

	3. The world of the external  and objective 

The significant issue is these are incommensurate.  This needs saying again - the three worlds are *incommensurate*, i.e completely and totally independent.

The implication is you cannot prove the truth of anything in one world using observations from  the other worlds. In an essential way, they are not causally linked.

In each, proof is only valid within its own world.

For example, in the limit,

	You cannot look at external reality (external world)  and prove the truth what an individual is feeling (subjective world) 

	You cannot make tests  in the theory world  that prove what happens in the external world.

And, obvious if you think about it, but often erroneously presumed otherwise,

	You cannot make tests of physical reality (external world) or use feelings and opinions (subjective world) to prove the truth of a  theory (theory world)

 The testing of theory is in the theory world, against other theories. The testing of theories is via the elements and processes of that world - mainly correct reasoning.


Any attempt to do otherwise is 'false' (rather than being a wicked problem).

For theory it is useful if it is coherent with experiences in the other worlds. It is that, that is often checked rather than testing for validity and proof.

So....  The primary test of the validity or 'truth' of any theory is in terms of whether it is contradicted by other theories.  Usually, this is satisfied by whether theory can be  formally deduced by other theories (not tests in the external world or subjective experiences). In case of new radical theories, the contradiction test may be the only  possibility.

Whether  and how much a theory is *useful*  is identified  via exploring the extent of its  correspondence with the external and subjective worlds.

Over the last 20 years, there is a potential challenge to aspects of Popper's 'Three Worlds' model from cognitive neuro-science (Love, 1998). Potentially, in the limit by drilling to the details of the physical data-holding and processing of human neural pathways, there is the possibility of a conjoint between the physical, subjective and theory worlds. This is speculation for the moment.

Interestingly, it is possible to use Popper's Three Worlds model to usefully apply the understanding of incommensurability to items within  a single world (Love, 1998). For example:

	Theory as experienced in one's head (subjective world)

	Theory as its expression in formulas on paper (external world)

	Theory in essence, i.e. theory qua theory (theory world)

This observation of incommensurability is similarly useful in theory-making  the realm of design research:

	Design as subjectively experienced, thought, felt (subjective world) 

	Design activity as observed by others (external world)

	Theories about design activity (theory world)

All three are incommensurable and cannot be validated by tests in the other worlds. 

Hence, most design research (except in the theory world) is only about testing the usefulness of theory or how well it comports with what happens in those other two worlds.

References:
Love, T. (1998). Social, Environmental and Ethical Factors in Engineering Design Theory: a Post-positivist Approach. Perth, Western Australia: Praxis Education.
Popper, K. R. 1976, Unended Quest: an intellectual autobiography, Open Court, La Salle, Ill.

NB: PhD-Design is a publication and the main way that I publish.  if anyone finds this post useful, please reference it appropriately as authored by myself. 

Best wishes,
Terry
==
Dr Terence Love, FDRS, AMIMechE, PMACM, MISI
PhD, B.A. (Hons) Eng, P.G.C.E
School of Design and Art, Curtin University, Western Australia
Psychology and Social Science, Edith Cowan University, Western Australia
Honorary Fellow, IEED, Management School, Lancaster University, UK

PO Box 226, Quinns Rocks, Western Australia 6030
[log in to unmask]   +61 (0)4 3497 5848
==







-----Original Message-----
From: PhD-Design - This list is for discussion of PhD studies and related research in Design [mailto:[log in to unmask]] On Behalf Of Prof. Jurgen Faust
Sent: Monday, 17 December 2012 7:00 PM
To: Dr Terence Love
Subject: design theory testing

Hi All,


I was looking into the possibility to find some articles about 'testing of design theory' and I haven't found too many articles. 
As we all know that some of the active participants have written about the possible nature of design theory and its limits, they may have as well some suggestions how design theory, which isn't developed as a pure science of design, which is more developed as a design science may be tested?

Jurgen 


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