bb-- The following text is taken from a Martin Ryder and colleague's article
with the url
They write, in part:
We use the term *affordance* to describe a potential for action, the
perceived capacity of an object to enable the assertive will of the actor.
The term was coined by psychologist James Gibson
describe the action possibilities posed by objects in the real world.
There are many objects in our environment. Some we ignore, some we adapt to,
and some we appropriate for our assertive will. It is the objects in this
last category which fall under the the definition of *affordances*. Certain
objects *afford* opportunities for action. An affordance is a value-rich
ecological object that is understood by direct perception. Perception
informs the individual of affordances. Action transforms affordances into *
effectivities* which extend human capabilities (Allen and Otto,
Our own bodies are affordances. The eyes afford perception, the ears
listening, the hands manipulation, the tongue and vocal cords afford
utterances (Jonassen, Campbell and Davidson,
Natural affordances emerge into effectivities through use in conscious
activity. The hand of an infant, though attached, is a separate object. The
infant is amused by it, studies it, tastes it, touches other things with it.
Soon the infant learns to *use* the hand to manipulate other objects. In the
process, the hand gradually transforms its object-ness to subject-ness. The
child becomes less conscious of the hand as she uses it as an extension of
her own intentioned will. The *affordance* becomes an *effectivity*.
Technology and media are affordances to the extent that they promise
extended human capabilities of seeing, hearing, and uttering. Tools are
affordances to the extent they offer extended human capabilities for
manipulating things in the environment. (Rasmussen, et. al.,
Through use, skill is acquired and the object becomes an extension of
These artifacts are transformed from affordances to effectivities.
Lots to think on here
On 1/22/06, bb <email@example.com> wrote:
> I'm still working on understanding the affordance-effectivity relation,
> I understand your hanging texts example the best, as I use something
> for teaching a course in child development -- students bring in drawings
> have solicited from children of any age up to adolesence and we post them
> the wall. The more, the better. Patterns emerge from *their* data, and
> see developmental progressions in the drawings, always with variations,
> definitely patterned. From this, many students eyes gleam with
> and I sense, without testing, that they have groked the development of
> independent performance.
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