bnevin@CCH.BBN.COM ("Bruce E. Nevin") (11/08/88)
In AIList Digest for Monday, 7 Nov 1988 (Volume 8, Issue 121), in a message dated 31 Oct 88 2154 PST on the topic "AI as CS and the scientific epistemology of the common sense world", John McCarthy <JMC@SAIL.Stanford.EDU> has persuasive words for colleagues who prefer to limit their research to things that are amenable to tidy mathematical formulation. The audience of "neats" he was addressing should ignore this. I want to talk about aspects of common sense that seem even less tidy. (But there is hope, cf. references at the end.) JMC> Intelligence can be studied | . . . | (3) through studying the tasks presented in the achievement of | goals in the common sense world. | . . . | I have left out sociology, because I think its | contribution will be peripheral. | . . . | AI is the third approach. It proceeds mainly in computer science There is more to common sense than the study of tasks and goals specified in physical terms. Much of common sense involves social facts, not just physical facts. A telltale of social facts is that they are matters of convention. Absent intelligent agents conforming to them, they do not exist. Restricted to physical facts, common sense concerns things like "I can't put the blue pyramid in the box, it's already in there" or "I can't put the lintel on yet, I need to move the second column closer to the first." Suppose we had an AI equipped with common sense defined solely in terms of physical facts. This is somewhat like the proverbial person who knows the price of everything but the value of nothing. We deceive ourselves when we put labels on things like "road" or "vehicle" or even "arch" in a knowledge base. We have many expectations and other associations with these terms that a knowledge base lacks--unless we explicitly include those associations. If and when we do begin to include such associations (that line defines my lane, this is the slow-speed lane, drive on the right--unless in England or Sweden or . . . that joker's trying to pass me in the breakdown lane . . . this must be Boston . . . ) we are involved with the sociology of knowledge. Look at Erving Goffman on, say, presentation of self or interaction rituals. Look at W. Pearce (UMass Amherst) on communication rules and rules for constituting the social order. For starters. An AI must be responsive as a member of the social order if it is to be regarded as intelligent by humans. It does not need the physiological or psychological mechanisms of humans, but it does need to understand their conventions. Bruce Nevin bn@bbn.com <usual_disclaimer>
DPK100::DOURSON_SE@gmr.COM (Dourson) (11/17/88)
Bruce Nevin (#125, Mon, 7 Nov 88 11:21:08 EST), responding to
McCarthy (#121, 31 Oct 88 2154 PST), compares the common sense of
"social facts" with the common sense of physical facts. He
states,
"Suppose we had an AI equipped with common sense defined
solely in terms of physical facts. This is somewhat like the
proverbial person who knows the price of everything but the
value of nothing."
Knowledge of physical facts is an essential condition for knowing
the value of things. The value of any thing is determined by what
it contributes to a person's survival and happiness. The price of
a thing is determined by the resources and effort required to
create it. Money is the means by which we measure both a thing's
value and its price.
A person whose knowledge is defined solely in terms of physical
facts, i.e., in terms of reality, would know (or could determine)
both the value of anything (in terms of what it contributes to his
survival and happiness), and the price (in terms of his own
personal effort) he would have to pay to create it or to purchase
it from others. Such a person knows that there is no such thing
as a "social _fact_"; and that survival and happiness are facts of
reality rooted in the natures of existence and man, not matters of
"social convention".
A person who knows prices of things without knowing their value,
has never had to earn his money, his survival, or his happiness.
A person whose values are based on social conventions, does not
think or act for himself, i.e., is not independent, and could not
survive and be happy on his own.
People talk a lot about equipping an AI with common sense and
goals, but seldom about equipping an AI with values and the
ability to make value judgements. When they do mention values, it
is usually in terms such as "social 'facts'", "social
conventions", and so-called "higher values", all of which are a
lot of floating fuzzy abstractions that signify nothing.
A value judgement is a precondition for a setting goal, which in
turn is a precondition for thought and action carried out to
achieve the goal. Knowledge, common sense, and effort are means
to achieve the goal. A successful AI will have the ability to
identify and explain the value to itself of a thing, and to
measure the thing's price in terms of its own time and effort. The
values an AI holds will be based on its nature and the conditions
required for it to exist, function, and survive. These values
will not be a matter of "social convention".
McCarthy stated that sociology is peripheral to the study of
intelligence. I submit that it is irrelevant.
Stephen Doursonbnevin@CCH.BBN.COM ("Bruce E. Nevin") (11/28/88)
Subject: Re: Epistemology of Common Sense In AIList Digest for Wednesday, 23 Nov 1988 (Volume 8, Issue 131), we see a message submitted Wed, 16 Nov 88 19:47 EDT by Stephen Dourson (Dourson <"DPK100::DOURSON_SE%gmr.com"@RELAY.CS.NET>) in response to mine in #125, Mon, 7 Nov 88 11:21:08 EST), responding to McCarthy (#121, 31 Oct 88 2154 PST). Dourson presents a reductionist view that there are only physical facts, and that SD> "social 'facts'", "social | conventions", and so-called "higher values", all . . . are a | lot of floating fuzzy abstractions that signify nothing. Unfortunately, I can't understand his message. Nor can I respond to it. Nor can it constitute a response to mine. They cannot even be said to constitute messages. The physical facts are that there are oddly shaped icons projected in luminous phosphor on a rectangular surface in front of me, but the means to recognize them as letters, words, sentences, assumptions, conclusions, and so on are only fuzzy abstractions that have no bearing on their interpretation and their value. :-) Sure, my (hypothetical) robot can recognize physical facts. For example, it has sensors to distinguish colors, among them red, yellow, and green. But it also has to know that red in a certain context means to stop the car. That is a social fact, a matter of convention and law. SD> Knowledge of physical facts is an essential condition for knowing the | value of things. Perhaps you thought I was denying this? Social facts and physical facts are not in some kind of competition. Social facts are >>constituted of<< physical facts. This means that an identifiable configuration of physical facts `counts as' a given social fact. That hooded box hanging up there on the wire constitutes a traffic signal. The box is a physical fact, the fact that it constitutes a traffic signal is a social fact. The fact that I ought to govern my behavior in accord with the color of the light it has turned on is also a social fact. If I fail to do so, and a crossing truck wrecks my car, that is a physical fact. But it constitutes a range of social facts eventually involving liability, payment of damages, loss of privilege, and so on. Human behavior is rule governed (more accurately, rule oriented [Labov]). What this means is that these constitutive relationships may be formulated as rules. The literature to which I referred you investigates these regularities of human behavior. Language is an obvious example of social fact. Sounds and inscribed or projected shapes are physical facts. As soon as you start talking about phonemes (phonological contrasts of a language) and letters (graphological contrasts), you have involved yourself in social facts shared by the users of the given language. The contrast represented by l vs r is a fact in English, but not in Japanese. The physical facts are the same, but in one language they constitute a contrast that distinguishes words from one another, in the other language they do not. Sentences are not constituted directly of the sounds that form the physical basis of speech, they are constituted of words, which are constituted of morphemes, which are constituted of phonemes, which finally are constituted of physical sounds. (Substitute your favorite linguistic terminology, the principle holds.) This is entirely characteristic of social facts: most social facts are constituted of more primitive social facts by which the relation to physical facts is mediated. It is not simple. There is much ambiguity: a given behavior counts as a persistent reminder for one person, as nagging for another. The fact that these conventions are not ordinarily matters of conscious introspection does not make their investigation easier. It even makes is possible for people to deny that they exist. :-) It is even crucial that some social facts be deniable or at least out of conscious awareness: their inaccessibility is our only assurance of sincerity. We assume that body language, for instance, does not lie. Hence, our profound distrust of salesmen and actors. Finally, this is not a matter of being a conformist, an individualist, or what have you. Unless you are a hermit in a cave somewhere your survival very much depends upon your facility with the social facts of your life. And even the hermit probably talks to himself. Bruce Nevin bn@bbn.com <usual_disclaimer>