From: markrose@spss.com (Mark Rosenfelder)
Newsgroups: comp.ai.philosophy
Subject: Re: grounding and the entity/environment boundary
Date: 7 Jan 93 18:09:45 GMT
Organization: SPSS Inc.

In article <C0GAxH.Jyw@gpu.utcs.utoronto.ca> pindor@gpu.utcs.utoronto.ca 
(Andrzej Pindor) writes:
>In article <C0EqIH.Ep4@spss.com> markrose@spss.com (Mark Rosenfelder) writes:
>>For the same reasons that toasters are not grounded w.r.t. making toast.
>>Groundedness has to do with whether your use of language has semantic
>>content; you have to have language use before you're even a candidate.
>>
>I have to disagree. Imagine a dumb and deaf person who learnt to play chess by
>watching. Is she/he less grounded w.r.t the game of chess than a language
>capable person? We are not talking here about grounding of language terms.
>To decide a question of the toaster we need a definition of grounding. I know 
>that some people are scared by the idea of having to define the terms they
>are using. I hope you are not one of them. You might say that any definition
>of grounding which would give even a slightest degree of grounding to a 
>toaster (w.r.t. making toast) is faulty, but I would disagree. Such an 
>attitude makes grounding by definition a property of humans only and the 
>whole discussion is then moot.

Grounding is whatever makes symbols mean something instead of just sitting
there squiggling and squoggling-- to some people, vast real-world experience;
to others, reference; and to Searle-- oh, forget Searle.

So no, not having symbols, toasters don't have even the slightest degree
of grounding.  

[do AIs need to be grounded to execute tasks for which humans need it:]
>>Consider a medical expert system written in Prolog.  It might well be able
>>to answer medical questions correctly without knowing anything about medicine
>>in any useful sense.  All it "knows" is statements like P(x) --> Q(x), 
>>and rules for manipulating them; the semantics is supplied entirely by
>>the user.
>>
>1. What do you mean by 'any useful sense'? If the expert system was able to 
>write a prescription for you, which you would then use, would it not be 
>'useful'?
>2. When we are discussing over the network, I type in a string of letters and
>get in a response another string of letters - P(x) --> Q(x), and it is me
>(the user) who supplies semantics. Things would be no different in principle
>if we were to discuss face to face. Those acoustic vibrations which you would
>produce would have no intrinsic semantics, I would have to supply the semantics
>entirely by myself. Do you agree? If you do not, please indicate where else
>would their meaning come from. 

If you're told that P(x) -> Q(x), and that P(m), you can deduce that Q(m).
But P and Q have no inherent semantics at all; they can represent any
predicates whatever.  That's what's nice about logic; but it's also what
makes the expert medical system know nothing about medicine.  The programmer
may interpret P(x) as "subject x has a runny nose"; but that doesn't mean
that the system knows anything about runny noses-- the programmer could
just as well have interpreted P(x) as "item x is on fire".
 
Human symbol systems are of course not *inherently* grounded-- "runny nose"
might mean "tasty breadfruit" in Maya-- but human beings *are* grounded:
when we make noises about noses or fire we aren't playing with arbitrary 
symbols, but really referring to noses or fire. 

Why is that?  Where does meaning come from?  For me, real-world experience.
There are other answers, but this one has the advantage of being compatible
with AI: grounding would be as available to robots as it is for humans.

Our using "grounding" in different senses probably makes hash of the 
discussion on how to test for it.
Newsgroups: comp.ai