[From Kent McClelland (2010.11.14.0930 CST)]
[From Bill Powers (2010.11.13.0815 MDT)]
Martin Taylor 2010.11.12.16.27 --
KM: In the exchange between Bill Powers and Martin Taylor about affordances, I agree with Bill about the difficulties of using the term "affordance". The problem with the term, as I see it, is that it attributes to an object or condition a property that is really the property of a relationship between that object and the organism making use of the object. An object has as many "affordances" as there are potential users of the object and potential uses that they might put the object to. So talking about "an environmental affordance" as if it were the property of the object alone is misleading.
I'm inclined to agree with Martin, however, in seeing the need for some reasonable way of talking about differences among the relationships between acting organism and parts of the environment that support (or don't support) their action. We can talk about an environment "offering" or "allowing" or "permitting" or "making easy" or "making impossible" or, to quote the nonscientific term that I used, "channelling" some action on the part of acting organisms within that environment, but all these ways of speaking seem open to the same objections as the word affordances.
The way I tried to discuss these relationships between environment and acting organism in the essay that I circulated was use Bill's language about "degrees of freedom" for a given organism in a given environment. This term, degrees of freedom, has the virtue, in my view, of locating the "agency" in the acting organism, not in the environment. But, as I think about it, I'm concerned that this way of speaking may also be open to some of the same objections.
In a post sent shortly after I posted my essay last week, Martin Lewitt had this criticism of my use of degrees of freedom:
[Martin Lewitt Nov 5, 2010 1420]
" . . . Degrees of freedom are discussed abstractly without any quantification. . . ."
I didn't respond at the time, because this criticism and his others in the post seemed somewhat wide of the mark to me, and they raised issues I wasn't eager to get into at that point, but I think Martin has put his finger on an issue that needs to be confronted.
My immediate reaction to Martin's comment was that trying to count degrees of freedom is ludicrous. We're talking about 800 or so degrees of freedom at any perceptual level, if I remember correctly the number given in Bill's article that I quote in my essay, and the precise number of degrees of freedom for a given organism in a given environment would vary enormously depending on what purpose the organism had in mind and what other perceptions the organism was trying to keep in control at the same time. And in some sense, the only numbers of degrees of freedom that matter for the organism are one and zero, either being able to control the perception or not.
But I still think it matters for the sociological arguments I would like to make for me to be able to characterize some environments as "rich" in degrees of freedom for people of a given culture (sets of widely distributed similar control systems for doing certain kinds of things), and other environments as relatively "poverty stricken" in degrees of freedom.
To make my arguments more concrete let me offer a couple of silly examples. If you're a birdwatcher and want to spot a pileated woodpecker, you probably wouldn't find one inside a WalMart store. Or if you're a gourmand and want an exquisite seven-course meal with a different fine wine for every course, you're not going to find that in a McDonald's. I'm not saying those things could never happen, but we can confidently predict that those environments are likely to offer few degrees of freedom for those purposes.
On the other hand, a WalMart or a McDonald's are comparatively rich in degrees of freedom for lots of other purposes, when compared to solitary confinement in a bare prison cell or a spot in a desert that's completely bare of vegetation, water, and any human-built structures.
It worries me though, that I can't give you a scientific way, even in principle, to enumerate the differences in degrees of freedom for certain kinds of organisms with certain kinds of purposes in those various environments.
So what's a more fruitful way to talk about the relationships between organisms and environments and about how some environments make certain things easier to do and other things harder?
My best,
Kent
···
MMT: I have the impression that you don't like using the word
"environmental affordance" as a short form for "feature of the
environment that can form part of an environmental feedback path"
because Gibson used the word.BP: It's true that I don't much like Gibson's work, but that's not
the reason I don't like "affordance" I think that nonliving things in
the environment have physical properties, but no psychological
properties. To speak of affordance as a property of something in the
environment is to endow it with characteristics that are not in it
(not in my model of the environment), but that exist only in the
viewer. It leads to objectification of things that are subjective,
like attributing "value" to objects in economics.MMT: I don't think that's a sensible reason, any more than it would
be sensible to complain about using "perception" as a short form for
"variable that changes as certain factors of the environment change"
on the grounds that most people take "perception" to mean something
of which one is conscious.BP: I agree, my dislike of Gibson's writings wouldn't be a sensible
reason for rejecting affordance as a property of the environment --
if that were my reason, which it isn't. In fact, it's the other way
around: I dislike Gibson's writings because they attribute
nonexistent properties to environmental objects. And that is quite
aside from the fact that "it's all perception." I just think that a
transitive verb like afford is a simple mistake in a model of the
non-living worldMMT: I think that if something affords an opportunity, the right
word for it is an affordance.BP: It would be, if things in the environment could do such a thing.
I don't think they can; the term is a metaphor. It's as if the object
were telling us what it could be used for -- which of course is
precisely what Gibson claims.The stones someone placed for crossing a small creek do not do
anything but be where they are and be flat on top. I could use them
for crossing the creek, or for placing my fishing gear on while I
wade beside them, or to start building a dam, or as foundations for a
bridge, or to provide a point of interest in a painting or a
photograph, or to study flow patterns, or to give evidence that
another person has been there, or to pry up and use to build a fire
pit on the shore, or to tie my boat to -- pretty smart stones, to be
able to afford all those uses, as well as many others I was too
insensitive to notice. Think of the incredible variety of affordances
that are obtained when iron, copper, or aluminum ore is mined; we may
never discover all of them. One would think that chemists would have
detected them by now.MMT: Thick ice on a lake surface is an affordance for snowmobilers,
fishers, skaters, ice-yachters... The use of an affordance for one
purpose in no way detracts from its use for another purpose unless
resource limitations come into play.BP: The metaphor can be carried as far as you wish, and that's fine
for poetry or simply colorful communication or entertainment. But I
don't think it has a role in any scientific discussion of how things
work. Nonliving objects do not have a property of affordance, nor can
they actively afford uses to people. As soon as you start trying to
explain how affordance works, you have to begin talking about human
goals and actions, and physical properties of feedback functions. A
serious model doesn't contain a variable or function called affordance.BP earlier: And one person's affordance is another person's
disturbance, as would probably have been the case if I had used
someone else's precious laptop to prop the door open.MMT:" The environmental affordance itself would not be a
disturbance, at least not as I think of disturbances.BP: Of course it would. I'm using someone else's laptop for a purpose
of my own in a way that might damage it, and that is definitely
something that would cause an error signal in most owners of laptops
-- if only in their imaginations, but perhaps also in present time
perception. "Look at that, you've scratched the case!"MMT: It's a state of the perceived environment. That state may not
correspond to the reference value of someone else's controlled
perception. But if all perceived states of the world that don't
match our reference values are called disturbances, what do you call
the changes of state that would in the absence of control move a
perception away from it reference value? I tend to use "disturbance"
to refer to the changes rather than to the static states. After all,
very little of our world matches our ideal world.BP: Put the straw man away, Martin. A disturbance is something that
affects the state of a controlled variable in a way that causes an
error signal in someone's control system. The resulting state does
"not correspond to the reference value of someone else's controlled
perception." What did you think I meant by "disturbance?" Isn't that
what you mean? If someone sees me pick up his laptop, set it down on
the floor, and push it with my foot against the bottom of the door to
keep it open, is that not a "dynamic" enough disturbance for you?
You're playing tricks with connotations that shift in the middle of a
paragraph: starting with disturbance (formally: something that
changes the state of a controlled perception independently of a
control system's action), then shifting to something that is just
different from a reference value for any reason, and ending with
things that would change a variable "in the absence of control." I
wasn't talking about the absence of control, but of its presence in
the person who objects to my using his laptop in a particular way,
even though it obviously (to me) "affords" that use. It's not my
fault that it obviously affords that use, is it? That convenient
excuse is one of the reasons people like to objectify their private
preferences.MMT: Anyway, that's not really the point of Kent's work, which is
that a network of controllers tend to generate an environment of
greater stability than would any one controller acting alone.BP: I don't think "stability" is the word you want in control-system
context. When people construct things that will last for a long time,
those things can be used for any purpose a person might invent to use
them for. But simply because they are semi-permanent, they also
present problems for other people whose controlled variables are
disturbed by those constructions, like the wall the Israelis built
between the Palestinians and the fields they farmed, or the highway
some politician finagled across what most local residents wanted to
be open space.MMT: If a network of control systems tend to rigidly stabilize some
features of the environment through a mixture of conflict and
(deliberate) cooperation, then those features can be stable
environmental affordances for control of quite independent
perceptions. Their stability allows control system structures to
reorganize to use them. Linguistic and cultural patterns have this
characteristic.BP: I have no argument with that. Now you're just talking about the
physical properties of whatever was created. Sometimes people try to
use those properties as means of control and discover that they are
wrong for the job; quite often they are good enough to allow a
reasonable degree of control. The physical properties of the feedback
function create multiple relationships between the action and the
local variables in which the controlled variable is perceived. But
the number of higher-order purposes for which those variables might
be used is probably uncountable.MMT: I tend to think of the rigidity of networking as somewhat
analogous to Buckminster Fuller's tensegrity structures (of which I
saw a marvellous example at the Science Centre at Baltimore Harbour
a couple of weeks ago). They hold themselves up because of the
entire structure. If you remove some cable or rod, the rest might or
might not remain stable, but you can be sure that no hitchup of a
couple of rods or cables by themselves would do so.BP: All true, and I'd be happy to see the subject discussed in that
way without attributing any active role in those structures for
determining what purposes a person might use them for.BP earlier: I think that "accidental" cooperation is much like the
correlation between two variables that is actually the result of a
third variable affecting them both: an illusion. You can
distinguish intentional from accidental cooperation by watching
what happens when various disturbances affect whatever it is that
both parties seem to be cooperating in accomplishing. When you
start seeing one person reacting against some disturbances and the
other person not reacting, you will know that the cooperation is
accidental and therefore illusory.MMT: True, but how is that comment relevant?
Don't you remember? You and Rick were also discussing cooperation. I
should have labeled the change of subject.Best,
Bill P.
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