Abram: The parameter 'k' does not really depend on the future, because it makes no assumption about what will happen in that period of time. It is just a "ruler" or "weight" (used with scale) to measure the amount of evidence, as a "reference amount".
For other people: The definition of confidence c = w/(w+k) states that confidence is the proportion of current evidence among future evidence, after the coming of evidence of amount k. Pei On Sun, Oct 12, 2008 at 1:48 PM, Abram Demski <[EMAIL PROTECTED]> wrote: > Pei, > > In this context, how do you justify the use of 'k'? It seems like, by > introducing 'k', you add a reliance on the truth of the future "after > k observations" into the semantics. Since the induction/abduction > formula is dependent on 'k', the truth values that result no longer > only summarize experience; they are calculated with prediction in > mind. > > --Abram > > On Sun, Oct 12, 2008 at 8:29 AM, Pei Wang <[EMAIL PROTECTED]> wrote: >> A brief and non-technical description of the two types of semantics >> mentioned in the previous discussions: >> >> (1) Model-Theoretic Semantics (MTS) >> >> (1.1) There is a world existing independently outside the intelligent >> system (human or machine). >> >> (1.2) In principle, there is an objective description of the world, in >> terms of objects, their properties, and relations among them. >> >> (1.3) Within the intelligent system, its knowledge is an approximation >> of the objective description of the world. >> >> (1.4) The meaning of a symbol within the system is the object it >> refers to in the world. >> >> (1.5) The truth-value of a statement within the system measures how >> close it approximates the fact in the world. >> >> (2) Experience-Grounded Semantics (EGS) >> >> (2.1) There is a world existing independently outside the intelligent >> system (human or machine). [same as (1.1), but the agreement stops >> here] >> >> (2.2) Even in principle, there is no objective description of the >> world. What the system has is its experience, the history of its >> interaction of the world. >> >> (2.3) Within the intelligent system, its knowledge is a summary of its >> experience. >> >> (2.4) The meaning of a symbol within the system is determined by its >> role in the experience. >> >> (2.5) The truth-value of a statement within the system measures how >> close it summarizes the relevant part of the experience. >> >> To further simplify the description, in the context of learning and >> reasoning: MTS takes "objective truth" of statements and "real >> meaning" of terms as aim of approximation, while EGS refuses them, but >> takes experience (input data) as the only thing to depend on. >> >> As usual, each theory has its strength and limitation. The issue is >> which one is more proper for AGI. MTS has been dominating in math, >> logic, and computer science, and therefore is accepted by the majority >> people. Even so, it has been attacked by other people (not only the >> EGS believers) for many reasons. >> >> A while ago I made a figure to illustrate this difference, which is at >> http://nars.wang.googlepages.com/wang.semantics-figure.pdf . A >> manifesto of EGS is at >> http://nars.wang.googlepages.com/wang.semantics.pdf >> >> Since the debate on the nature of "truth" and "meaning" has existed >> for thousands of years, I don't think we can settle down it here by >> some email exchanges. I just want to let the interested people know >> the theoretical background of the related discussions. >> >> Pei >> >> >> On Sat, Oct 11, 2008 at 8:34 PM, Ben Goertzel <[EMAIL PROTECTED]> wrote: >>> >>> >>> >>> Hi, >>> >>>> >>>> > What this highlights for me is the idea that NARS truth values attempt >>>> > to reflect the evidence so far, while probabilities attempt to reflect >>>> > the world >>> >>> I agree that probabilities attempt to reflect the world >>> >>>> >>>> . >>>> >>>> Well said. This is exactly the difference between an >>>> experience-grounded semantics and a model-theoretic semantics. >>> >>> I don't agree with this distinction ... unless you are construing "model >>> theoretic semantics" in a very restrictive way, which then does not apply to >>> PLN. >>> >>> If by model-theoretic semantics you mean something like what Wikipedia says >>> at http://en.wikipedia.org/wiki/Formal_semantics, >>> >>> *** >>> Model-theoretic semantics is the archetype of Alfred Tarski's semantic >>> theory of truth, based on his T-schema, and is one of the founding concepts >>> of model theory. This is the most widespread approach, and is based on the >>> idea that the meaning of the various parts of the propositions are given by >>> the possible ways we can give a recursively specified group of >>> interpretation functions from them to some predefined mathematical domains: >>> an interpretation of first-order predicate logic is given by a mapping from >>> terms to a universe of individuals, and a mapping from propositions to the >>> truth values "true" and "false". >>> *** >>> >>> then yes, PLN's semantics is based on a mapping from terms to a universe of >>> individuals, and a mapping from propositions to truth values. On the other >>> hand, these "individuals" may be for instance **elementary sensations or >>> actions**, rather than higher-level individuals like, say, a specific cat, >>> or the concept "cat". So there is nothing non-experience-based about >>> mapping terms into a "individuals" that are the system's direct experience >>> ... and then building up more abstract terms by grouping these >>> directly-experience-based terms. >>> >>> IMO, the dichotomy between experience-based and model-based semantics is a >>> misleading one. Model-based semantics has often been used in a >>> non-experience-based way, but that is not because it fundamentally **has** >>> to be used in that way. >>> >>> To say that PLN tries to model the world, is then just to say that it tries >>> to make probabilistic predictions about sensations and actions that have not >>> yet been experienced ... which is certainly the case. >>> >>>> >>>> Once >>>> again, the difference in truth-value functions is reduced to the >>>> difference in semantics, what is, what the "truth-value" attempts to >>>> measure. >>> >>> Agreed... >>> >>> Ben G >>> >>> ________________________________ >>> agi | Archives | Modify Your Subscription >> >> >> ------------------------------------------- >> agi >> Archives: https://www.listbox.com/member/archive/303/=now >> RSS Feed: https://www.listbox.com/member/archive/rss/303/ >> Modify Your Subscription: https://www.listbox.com/member/?&; >> Powered by Listbox: http://www.listbox.com >> > > > ------------------------------------------- > agi > Archives: https://www.listbox.com/member/archive/303/=now > RSS Feed: https://www.listbox.com/member/archive/rss/303/ > Modify Your Subscription: https://www.listbox.com/member/?&; > Powered by Listbox: http://www.listbox.com > ------------------------------------------- agi Archives: https://www.listbox.com/member/archive/303/=now RSS Feed: https://www.listbox.com/member/archive/rss/303/ Modify Your Subscription: https://www.listbox.com/member/?member_id=8660244&id_secret=117534816-b15a34 Powered by Listbox: http://www.listbox.com
