Pei, Good post. Ed Porter -----Original Message----- From: Pei Wang [mailto:[EMAIL PROTECTED] Sent: Saturday, October 13, 2007 11:29 AM To: [email protected] Subject: [agi] "symbol grounding" Q&A
Hi, The current discussion on symbol grounding, to me, includes several different (though related) questions. In the following, I'll try to separate them, and give my opinion on each of them. *. When is a symbol "grounded"? A symbol is grounded when its meaning to the system is determined according to the system's experience on the symbol. *. What is wrong in traditional "symbolic AI" on this topic? In those systems, the meaning of a symbol is determined by an "interpretation", which takes the meaning of the symbol to be an object/entity in the world that is "referred to" by the symbol. In this way, the system's experience plays no role, and a symbol can be interpreted in many different ways. *. What is the "experience" needed for symbol grounding? Any input-output activity that happens between a system and its environment. *. For the symbols in an AGI to be grounded, should the experience of the system be the same, or very similar, to human sensory experience? No. The system can ground its symbols in experience that is very different from human experience, as far as "intelligence" is concerned. *. Is vision necessary for symbol grounding in AGI? No, for the above reason. *. Is vision important in deciding the meaning of human concepts? Yes, since vision is a major channel of human experience, the meaning of many human concepts include visual components. *. In that case, if an AGI has no vision, how can it still understand a human concept? "Understanding" is a matter of degree. Since the meaning of a symbol is determined by the system's experience about it, it will have different meanings in different systems, though as far as the systems' experience have overlap, the symbol will have common meaning in these systems. If an AGI's does not have visual experience, it won't understand a concept exactly as a human, though its other experience channels may allow the understanding to be close to a human understanding. *. Can a blind person to be intelligent? According to the above opinion, a blind person can be perfectly intelligent, with symbols grounded in (non-visual) experience. However, there will always be some difference in what certain concepts mean to such a person, compared to the "normal" people. *. How can a sensorless system like NARS have grounded symbol? In principle, as far as a system has input, it has sensor, though its sensor can be very different from human sensors. The mistake of traditional symbolic AI is not that the systems have no sensor (or have no body), but that their experience play no role in determining the meaning of the symbols used in the system. Since in NARS the meaning of symbols (i.e., how they are treated by the system) is determined by the system's experience, they are grounded. Of course, since NARS' experience is not human experience, the same symbol usually have different meaning to it, compared to its meaning to a human being. *. If NARS always uses symbols differently from typical human usage, can we still consider it intelligent? Yes we can. Even among human beings, the same word often means different things --- just see what happens in this mailing list! We should not treat "different understanding" as "no understanding". Very often, my understanding of English is still different from a native English speaker, but I guess I can say that I understand English, in my way. For this reason, when I meet someone who have a different understanding on a concept, I usually don't conclude that he/she has no intelligence. ;-) *. Are you saying that vision has nothing to do with AGI? Of course not! I'm saying that vision is not a necessary component of an AGI. Since vision plays an important role in human cognition, there are practical reasons for certain AGI projects to include it to ground concepts in a more "human-like" manner, though some other AGI projects may exclude it, at least at early stage. Again, intelligence can be achieved without vision, or any other human sensory channel, though it will have an impact on the meaning of the symbols in the system. More "academic" treatments of this topic: http://nars.wang.googlepages.com/wang.semantics.pdf http://nars.wang.googlepages.com/wang.AI_Misconceptions.pdf Pei ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?&; ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?member_id=8660244&id_secret=53678059-3da78b
