Affordances! Ah, how can I resist.
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On Tue, Feb 7, 2012 at 5:39 PM, CHUA Soo Meng Jude (PLS)
<[log in to unmask]> wrote:
I was speaking to a colleague in another department about my musings
on semiotics and photography, or the camera and he introduced this
idea of affordances to me.
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So here is a brief review of my understanding of affordances,
including how I came to introduce this notion into design. This is a
biased account: I am certain that others on this list will be able to
correct my biases.
J. J. Gibson was a noted scholar of perception. He was originally a
Gestalt psychologist, which you could argue was a predecessor to
cognitive psychology, but he then renounced all of this and decided
that the world was rich with information, so perception should be
thought of as the automatic pickup of this information -- no mystical
brain processes required. He also treated perception as a system:
motor movements, vision, proprioception, sound, taste, feel, etc.
Among the concepts he introduced was that of affordance: the
relationship between an organism and the environment. Affordances
permitted different kind of actions, depending upon who and what the
organism was and the state of the environment. Affordances, said
Gibson, exist, even if they are not perceived or known by the
organism.
I met Gibson for the first time in the 1970s, and then spent
considerable time debating and arguing with him, often over drinks
late into the evening for many years when he used to visit the
University of California, San Diego (in La Jolla, a suburb of San
Diego), where I was a professor. I thought his ideas brilliant,
insightful, impractical, crazy, and sometimes just simply wrong. And
sometimes absolutely, wonderfully right.
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Pause. Move to the 1980s. I was in England, writing the book The
Design/Psychology of Everyday Things (DOET). One of the puzzles I
worried about was how we managed to survive so well in a world filled
with novel objects. We continually encounter new things, controls,
devices, yet we manage quite well. How can this be, I wondered. I
slowly began to realize that the devices themselves signaled how they
were to be used (or perhaps avoided). That is, there is knowledge in
the world. This brought me back to my many debates with Gibson, and I
realized that I could appropriate his idea of affordance for the
problems of design. If you could perceive an object's affordances, you
would know how to behave.
Note that I said "perceive." So I was distorting Gibson's ideas --
very deliberately. First, the affordances had to be perceivable --
Gibson did not require this. Second, the person had to be able to
interpret them. Gibson thought that nonsense -- or rather,
unnecessary: he thought interpretation was automatic. So, my notion
of affordance differed from that of Gibson. On purpose.
I was careful in DOET to state that I was talking about Perceived
Affordances, and that not all affordances were perceivable. Moreover,
there are false affordances -- things that look like affordances but
aren't. I wrote several essays in which I pointed out that every place
"DOET referred to affordances, replace it with "perceived
affordances." (I had stated this in the book, but I said I would use
the one word instead of the two words -- that was a mistake because
people ignored my statement.)
My notion of affordance was widely picked up by the design and
engineering communities. But although I had deliberately changed the
notion to make it more appropriate to design, designers and engineers
often unwittingly distorted both of our notions to make it fit their
preconceptions and needs.
One problem, which I have written about, is that designers needed a
way to talk about the signs/symbols they placed upon their designs to
communicate the ways in which it should work. Thus, consider the
scroll bar of a window on a computer display. Designers would say "II
put an affordance there." I realized that although this was an
erroneous use of the concept, the designers had no other way of
describing what they had done, so they appropriated affordance as the
closest thing.
http://www.jnd.org/dn.mss/affordances_and_design.html
http://www.jnd.org/dn.mss/affordance_conventions_and_design_part_2.html
http://jnd.org/dn.mss/design_as_communication.html
That's the way language changes, I said, so OK, that's a good thing.
Signifiers
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In my most recent work, I have introduced the term Signifier.
(Borrowed, with modification, from Semiotics). I define the term
"signifier" to represent the perceivable aspect of an affordance. But
a signifier can also represent simple communications with no
affordances at all.
http://jnd.org/dn.mss/signifiers_not_affordances.html
I discuss this in my essays and in most detail in my most recent book,
Living With Complexity.
My essays on the topic
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If you want to follow my arguments, go to my website -- www.jnd.org
-- and type the phrase "affordance OR signifier" into the search
window. That gives you the numerous essays where I have expanded upon
these ideas. Alternatively, go to Google and type this search string:
"site:jnd.org affordance OR signifier"
Jude's question:
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Jude Asked:
"But think of how a portrait photographer and Walter Benjamin would
use the camera; one just to take a picture of something aiming at an
aesthetic image, another as a tool for critical consciousness raising.
Can we then say these two persons read in the camera very different
"affordances"?"
That's a very interesting discussion. When a photographer recognizes
that such things as deliberate distortion of focus, or lighting, or
perspective produces new insights in the resulting images, yes, I
believe you could say that the photographer has discovered new
affordances (deliberately degrading focus, or applying petroleum jelly
to the lens) that help produce the desired impact.
Consider photographs of moving water. We are used to pictures with
fairly short exposure times, so the water in the stream or waterfall
is seen either completely stopped in its motion or with a slightly
blurred look that we now interpret as the sign of motion. But some
photographers have been experimenting with very long shutter times, so
that the water (or fields of weaving grain weaving in the wind) appear
as non-discriminable blurs.
see http://www.digital-photography-school.com/long-exposure-photography
Yes, I would say they have discovered and exploited the affordances.
Now, this may not answer Jude's question because Walter Benjamin was a
complex thinker. I leave this to Jude.
Other literature
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By now, there is a voluminous literature on affordances, some very
insightful, some weird, wrong, misguided. You will find it in design,
psychology, engineering (and engineering design) and philosophy. I
will not attempt to summarize: I'll let you struggle through it. But
let me mention two strands:
Bill Gaver, who was one of my PhD students, has written quite
extensively about Information Affordances, and how the notion can be
applied to information design. He did this while he was at RCA, in
London.
Clarisse de Souza, in Brazil, has discussed the role of communication
in design through what she calls "Semiotic Engineering." I think this
a very powerful extension of the ideas of design as communication,
merging affordances, signifiers, and the field of semiotics.
.
Don
Don Norman
Nielsen Norman Group
[log in to unmask] www.jnd.org
http://www.core77.com/blog/columns/
Latest book: "Living with Complexity"
IDEO Fellow.
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