As I started responding to the questions asked of me, I ended up writing an
essay. So this stands as an independent contribution. Indeed, I changed the
title on the subject line to reflect this change.
Note that when I introduced the term "affordance" into design, I deviated
somewhat from J.J Gibson's intentions for the term. (He and I used to argue for
many long, lovely hours about the nature of perception. I disagreed with much of
what he said, but thought that the disagreements were among the most informative
and productive of my career. Judging by the twinkle in his eyes, I know he
enjoyed them as much as I. He frequently overstated his case to make a point --
and when we had both had drunk enough, he would admit it.)
To Gibson, affordances exist in the world as relationships between agent and
object. It does not matter if anyone ever discovers them. To me, not only
should affordances be perceivable to be useful, but I have generalized the term
to include emotional affordances, social, cultural, ontological, ... etc. J.J
would not approve. Moreover, one can have false affordances, when a designer (or
nature) deliberately puts in signals so as to mislead. Hiding doors, placing
false eyes on the wings of butterflies, putting steel-looking rods to block a
car's path (even though they are rubber, so knowing drivers can just drive right
over them). To Gibson, the notion of a false affordance would be abhorrent.
Note too that modern-day graphics and interaction designers have distorted the
term even more, saying such things as "I put an affordance there," when in fact,
they simply put a visual objection the screen and assigned an action to be
performed if it were to be clicked upon. Technically, one can always click on
any part of the screen, even if nothing is being displayed, but this is not a
very useful sense of the term "affordance." The designer's sense, although
technically wrong, is useful. In several essays on my website, I discuss this
change in meaning. Eventually I have come to accept the changes: there is no
other term to describe what designers are doing, and affordance was available,
and close to the meaning. That is how language changes -- through borrowing and
explanation. Purists have objected. I am not a purist.
Now, Keith Russell asked me some questions about mysterious coke bottles,
affordances, and visceral, behavioral, and reflective design. (If you haven't
seen the movie "The Gods Must Be Crazy" you will not get the reference. I
recommend the movie. But basically, a coke bottle falls mysteriously out of the
sky in a remote African village (having been dropped by a passing airplane), so
people who had never seen such a thing before try to infer its deep meaning and
significance.)
Keith suggests:
> Scene one where the bottle arrives is the Visceral moment
>
> Scene two where the bottle is given its Affordances (some
> social, some ontological), is the Behavioral moment.
>
> Scene three where they try to dispose of the offending object
> (abject) is the Reflective moment.
>
To a very, very rough first approximation, those are appropriate statements, but
the approximation is very rough. Let me explain why.
I have defined Visceral design as perceptually-driven, yielding automatic
emotional (technically, affective) responses that are the same for all people,
all cultures. These are perceptually-driven, so they only encompass simple
states such as liking or disliking, good or bad, safe or dangerous. (Fear of
heights, crowds, the dark, and dislike of bitter tastes, liking of sweet ones
are all visceral responses. Liking bright colors and symmetrical faces as well.)
So in some sense, the first perception of the coke bottle leads to a visceral
response, but it immediately gets tied up with the attempt to understand it -- a
cognitive act that in my theory is mostly reflective, and a little bit
behavioral.
Definitions: Both cognition and emotion are the result of information processing
structures within the brain:
Cognition refers to the operations that understand and interpret the world.
Emotion: refers to the operations that judge and evaluate the world.
Emotion often precedes cognition, although cognition can drive emotions.
Cognition and emotion cannot be separated -- they work together in tandem, and
each heavily affects the other. Thus, cognition processes information
differently when in a negative emotional state (negative valence) than when in a
positive emotional state (positive valence). (Its more complex than that, but
that's a start.)
So, sure, the coke bottle starts off at the Visceral level, but goes on quickly
to the others.
---
Affordances refer to the set of possible actions upon an object -- always
relative to the agent (or person, in this case). Actions are, of course,
behavioral. So, in that sense, the second stage is indeed Behavioral. The coke
bottle affords lifting, seeing through, throwing, filling-up, supporting, etc.
But the contemplation of the set of possibilities, and any discussion of its
social or ontological status is Reflection.
According to the theory, Visceral and Behavioral responses are subconscious.
Both levels of processing take in perceptual information and control muscle
movements -- actions. Reflection is conscious. It is a meta-level activity --
it looks at the person's own behavior and makes judgments. It can try to control
actions, but only by influencing the lower levels. This is the home of
consciousness, of full-fledged emotions, of feeling, and of self image.
Finally, the statement that:
> ... the bottle is given its Affordances (some social, some ontological) ...
is contradictory to the notion of affordance, at least as both Gibson and I have
defined it. The bottle and person always have affordances because of the
physical properties of both the bottle and the person. So affordances can only
be discovered, not given.
Now, when we move to non-physical affordances, the story is more complex. I
claim that a camera -- especially a camera phone -- provides emotional
affordances. It makes possible the capturing, sharing, and preservation of
important emotional events. So perhaps a photo -- or a coke bottle -- can be
given emotional, social, and ontological affordances.
That's an interesting expansion of the concept.
---
Sorry for the long answer, but it was an excellent, thought-provoking question.
Don Norman
Donald A. Norman
Nielsen Norman Group http://www.nngroup.com
[log in to unmask] http://www.jnd.org
And, until August 2004, part time Prof. Computer Science and Psychology
Northwestern University, [log in to unmask]
(In August, I move to Palo Alto, CA)
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