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On Design Theory

There exists some dispute about the nature and role of theory in design (writ large). Here, I track my own thoughts on the subject.


I have participated in various discussion threads in the mailing list (archives available at here) involving the nature of theory in design.

Some discussions have evolved into questioning the nature of theory in general, on the premise that clearly defining what constitutes a theory of any sort is precursive to defining what a design theory is or might be.

In time, I hope to incorporate the actual comments made in those discussions here. For now, however, it is home to my take on the matter, which is in no small part driven by what I've read. TBD

What is Theory?

I like to start with dictionary definitions, because they tend to capture the most common features of the common usages of terms. This lets one start with notions rooted in the culture and history, as well as most likely appealing to the most number of people.

My two favourite sources of “dictionary” definitions are * Google ( * Wiktionary (

Reading these definitions – and excluding those with highly specialized meanings (e.g. a theory in formal logic), it becomes quickly apparent that the common theme is:

A theory is an internally consistent explanation the validity of which is not apparent.

There are three key features here: internal consistency, explanation, and validity (or lack thereof).

Consequences of Internal Consistency


Consequences of Explanation

Explanation requires an object and a subject. That is, one explains something other than oneself.

  • Even if one seeks to explain oneself, one does so by assuming a role in principle detached from the role of being explained.
    • Whether this is ultimately possible in a perfect way is debatable.
    • But there are cases where this is presumably possible – consider the astronomer explaining the existence of some celestial object millions of light years away.
      • It is difficult to imagine that any significant connection exists between the two.
        • Except in the most philosophical sense (?)
  • The separation of subject and object evolved in humans.
    • An organism co-exists and constantly interacts with its environment.
    • If this interaction is constant, then how do humans know where they end and their environment begins?
    • The I of consciousness distinguishes between what it can control and what it can't.
      • This conscious sense is augmented by information made available to the brain sub- and un-consciously.
        • The brain, for instance, interacts with the heart unconsciously, but there remains some connection between the conscious part of the brain and the heart, mediated by the unconscious brain. We can consciously reason to a conclusion that scares us, and our hearts will respond accordingly.
    • This distinction is the basis of the separation of subject and object.

The separation of object and subject leads one to consider the role of perception in how we theorize/explain.

  • One's mind – the thing that does the explaining – is separated from “reality” (whatever that is) by one's perceptions.
  • Perceptions act as very strong filters on what the mind has access to from “reality”.
    • Refer to MindHacks, a very interesting book about what the brain does for the mind, to see just how powerful these perceptual filters can be.
  • Perceptions of an object can be confounded by influences from other sources, including the subject itself.

So, an attempt is made (especially in science) to control the influence exerted by external sources on the object.

  • Once upon a time, isolation of the object from external influences may have been an ideal.
    • But this is no longer so. The notion of dynamic systems continues to emerge as a better way to treat complex entities.
  • Controlling external influences within reasonable physical limits continues to be a goal of research, however, because it allows study of the individual object rather than the complex of the object in its surroundings – its interactions with other objects. The capacity of such theories to completely explain is known to be limited, but also known to be essential.
  • Since the behaviour of a collective of objects arises from the interactions between the elements of the collective, it is valuable to understand how the individual – as well as the collective – operate/behave/function.

Consequences of Validity


Branches of Design

I take as axiomatic that there is a discipline of design that is independent of design-as-practised in any particular discipline.

It follows that the current division of design by discipline is largely hindering the advancement of design, and gives opportunity to others to co-opt the term and therefore dilute its meaning.

Furthermore, many of the distinctions between design in this discipline and design in that discipline are entirely artificial and unnecessary.

  • EG: the embedding of domain-specific knowledge in a design body of knowledge.

However, I also agree with the general principle that design can/does vary depending on where it is used.

So how does one resolve this apparent contradiction? By arguing that there are some divisions in design that make sense, and that these divisions can be logically identified.

For instance, I think two of those kinds of designing are engineering design and interaction design.

  • Interaction design is about the interactions between designed things and people (“users”).
  • Engineering design is largely about the interactions between designed things and other things.
  • Note, however, that there is still an underlying uniformity achieved by:
    • considering “users” to include both things and people, and
    • using systems thinking.
  • Of course, it does make sense to separate human from non-human users (but what about animal users?) because we have no control over that distinction.
    • But the distinctions between some other kinds of design are entirely artificial - we created them - they are not beyond our control.

See Also


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research/on_design_theory.txt · Last modified: 2020.03.12 13:30 (external edit)