It is true that Mark Waser did not provide much justification, but I think he is right. The if-then rules involved in forward/backward chaining do not need to be causal, or temporal. A mutual implication is still treaded differently by forward chaining and backward chaining, so it does not cause ambiguity. For example, if we have "An alarm sounds if and only if there is a fire", then a forward-chaining algorithm would (1) conclude that there is an alarm sounding if it learned that there was a fire, and (2) conclude that there was a fire if it learned that there was an alarm. A backwards-chainer would use the rule differently, so that (1) it might look for a fire if it was trying to determine if an alarm was sounding, and (2) it might look for an alarm if it wanted to know about a fire. Even though the implication goes in both directions, the meaning of forward chaining and of backward chaining are quite different.
On Mon, Jul 14, 2008 at 10:40 AM, Ed Porter <[EMAIL PROTECTED]> wrote: > Mark, > > Since your attack on my statement below is based on nothing but conclusory > statements and contains neither reasoning or evidence to support them, there > is little in your below email to respond to other than your personal spleen. > > > You have said my statement which your email quotes is "simply incorrect" > without giving any justification. > > Your statement that "Temporal criteria are *NOT* relevant to forward and > backward chaining" is itself a conclusory statement. > > Furthermore this statement about temporal criteria not being relevant is > more incorrect than correct. If an if-then rule describes a situation where > one thing causes another, or comes before it time, the thing that comes > first is more commonly the if clause (although one can write the rule in the > reverse order). The if clause is commonly called a condition, and the then > clause is sometimes called the consequence, implying a causal or temporal > relationship. The notion of reasoning backward from a goal being backward > chaining, normally involves the notion of reasoning back in imagined time > from a desired goal state. So often TEMPORAL CRITERIA *ARE* RELEVANT TO > WHICH DIRECTION IS FORWARD CHAINING AND WHICH IS BACKWARD. > > Even if one were to make a reach, and try to justify your statement that > "Temporal criteria are *NOT* relevant to forward and backward chaining" as > being more than just conclusory by suggesting it was an implicit reference > to statements --- like that contained Richard's prior statements in this > thread or the Wikipedia quote in one of the posts below --- that the > definition of forward and backward chaining depended on whether the > reasoning was from if clause to then clause, or the reverse --- that would > still not correct the groundlessness of your criticism. > > This is because the rule that forward chaining is from if clause to then > clause and the reverse for backward chaining has no applicability to > situations where the implication goes both ways and there is no clear > indication of which pattern should be the if clause and which should be the > then clause --- which is precisely the situation I was describing in the > quote from me you unfairly criticized. > > Neither Richard's prior statement in this thread nor the Wikipedia > definition below define which direction is forward and which is backward in > many such situations. > > In my quote which you attacked I was discussing exactly this situations when > it was not clear which part of an inference pattern should be considered the > if clause and which the then clause. So it appears your criticism either > totally missed, or for other reasons, failed to deal with the issue I was > discussing. > > Mark, in general I do not read your posts because, among other things, like > your email below, they are generally poorly reasoned and seemed more > concerned with issues of ego and personality than with learning and teaching > truthful information or insights. I skip many of Richard's for the same > reason, but I do read some of Richard's because despite all his pompous BS > he does occasionally say something quite thoughtful and worth while. > > If you care about improving your reputation on this list, it would make you > seem more like someone who cared about truth and reason, and less like > someone who cared more about petty squabbles and personal ego, if you gave > reasons for your criticisms, and if you took the time to ensure your > criticism actually addressed what you are criticizing. > > In your post immediately below you did neither. > > Ed Porter > > -----Original Message----- > From: Mark Waser [mailto:[EMAIL PROTECTED] > Sent: Monday, July 14, 2008 9:19 AM > To: agi@v2.listbox.com > Subject: RE: FW: [agi] WHAT PORTION OF CORTICAL PROCESSES ARE BOUND BY "THE > BINDING PROBLEM"? > >>> Anyone who reads this thread will know who was being honest and >>> reasonable > and who was not. > > The question is not honest and reasonable but factually correct . . . . > > The following statement of yours >>> In this case it becomes unclear which side is the "if" clause, and which >>> the "then" clause, and, thus, unclear which way is forward and which >>> backward by the definition contained in Wikipedia --- unless there is a >>> temporal criteria. > is simply incorrect. Temporal criteria are *NOT* necessarily relevant to > forward and backward chaining. > > As far as I can tell, Richard is trying to gently correct you and you are > both incorrect and unwilling to even attempt to interpret his words in the > way he meant (i.e. an honest and reasonable fashion). > > ----- Original Message ----- > From: "Ed Porter" <[EMAIL PROTECTED]> > To: <agi@v2.listbox.com> > Sent: Monday, July 14, 2008 8:58 AM > Subject: **SPAM** RE: FW: [agi] WHAT PORTION OF CORTICAL PROCESSES ARE BOUND > > BY "THE BINDING PROBLEM"? > > > Richard, > > You just keep digging yourself in deeper. > > Look at the original email in which you said "This is not correct." The > only quoted text that precedes it is quoted from me. So why are you saying > "Jim's statement was a misunderstanding"? > > Furthermore, I think your criticisms of my statements are generally > unfounded. > > My choice of the word "reasoning" was not "not correct", as you imply, since > the Wikipedia definition says "Forward chaining is one of the two main > methods of REASONING when using inference rules." (Emphasis added.) > > My statement made it clear I was describing the forward direction as being > from the if clause to the then clause, which matches the Wikipedia > definition, so what is "not correct" about that. > > In addition, you said my statement that in the absence of a temporal > criteria "the notion of what is forward and backward chaining might be > somewhat arbitrary" was a "completely incorrect conclusion." > > Offensively strong language, considering it is unfounded. > > It is unfounded because in the absence of a temporal distinction, many > if-then rules, particularly if they are probabilistic, can viewed in a two > way form, with a probabilistic inference going both ways. In this case it > becomes unclear which side is the "if" clause, and which the "then" clause, > and, thus, unclear which way is forward and which backward by the definition > contained in Wikipedia --- unless there is a temporal criteria. This issue > becomes even more problematic when dealing with patterns based on temporal > simultaneity, as in much of object recognition, in which even a temporal > distinction, does not distinguish between what should be consider the if > clause and what should be considered the then clause. > > Enough of arguing about arguing. You can have the last say if you want. I > want to spend what time I have to spend on this list conversing with people > who are more concerned about truth than trying to sound like they know more > than others, particularly when they don't. > > Anyone who reads this thread will know who was being honest and reasonable > and who was not. > > Ed Porter > > -----Original Message----- > From: Richard Loosemore [mailto:[EMAIL PROTECTED] > Sent: Sunday, July 13, 2008 7:52 PM > To: agi@v2.listbox.com > Subject: Re: FW: [agi] WHAT PORTION OF CORTICAL PROCESSES ARE BOUND BY "THE > BINDING PROBLEM"? > > Ed Porter wrote: >> Richard, >> >> I think Wikipedia's definition of forward chaining (copied below) agrees >> with my stated understanding as to what forward chaining means, i.e., >> reasoning from the "if" (i.e., conditions) to the "then" (i.e., >> consequences) in if-then statements. >> >> So, once again there is an indication you have unfairly criticized the >> statements of another. > > But ....... nothing in what I said contradicted the wikipedia > definition of forward chaining. > > Jim's statement was a misunderstanding of the meaning of forward and > backward chaining because he oversimplified the two ("forward reasoning > is reasoning from conditions to consequences, and backward reasoning is > the opposite" ... this is kind of true, if you stretch the word > "reasoining" a little, but it misses the point), and then he went from > this oversimplification to come to a completely incorrect conclusion > ("...Thus I think the notion of what is forward and backward chaining > might be somewhat arbitrary..."). > > This last conclusion was sufficiently inaccurate that I decided to point > that out. It was not a criticism, just a clarification; a pointer in > the right direction. > > > Richard Loosemore > > > > > > >> Ed Porter >> >> ==========Wikipedia defines forward chaining as: ============== >> >> Forward chaining is one of the two main methods of reasoning when using >> inference rules (in artificial intelligence). The other is backward >> chaining. >> >> Forward chaining starts with the available data and uses inference rules > to >> extract more data (from an end user for example) until an optimal goal is >> reached. An inference engine using forward chaining searches the inference >> rules until it finds one where the antecedent (If clause) is known to be >> true. When found it can conclude, or infer, the consequent (Then clause), >> resulting in the addition of new information to its data. >> >> Inference engines will often cycle through this process until an optimal >> goal is reached. >> >> For example, suppose that the goal is to conclude the color of my pet > Fritz, >> given that he croaks and eats flies, and that the rule base contains the >> following four rules: >> >> If X croaks and eats flies - Then X is a frog >> If X chirps and sings - Then X is a canary >> If X is a frog - Then X is green >> If X is a canary - Then X is yellow >> >> This rule base would be searched and the first rule would be selected, >> because its antecedent (If Fritz croaks and eats flies) matches our data. >> Now the consequents (Then X is a frog) is added to the data. The rule base >> is again searched and this time the third rule is selected, because its >> antecedent (If Fritz is a frog) matches our data that was just confirmed. >> Now the new consequent (Then Fritz is green) is added to our data. Nothing >> more can be inferred from this information, but we have now accomplished > our >> goal of determining the color of Fritz. >> >> Because the data determines which rules are selected and used, this method >> is called data-driven, in contrast to goal-driven backward chaining >> inference. The forward chaining approach is often employed by expert >> systems, such as CLIPS. >> >> One of the advantages of forward-chaining over backward-chaining is that > the >> reception of new data can trigger new inferences, which makes the engine >> better suited to dynamic situations in which conditions are likely to >> change. >> >> >> -----Original Message----- >> From: Richard Loosemore [mailto:[EMAIL PROTECTED] >> Sent: Saturday, July 12, 2008 7:42 PM >> To: agi@v2.listbox.com >> Subject: Re: FW: [agi] WHAT PORTION OF CORTICAL PROCESSES ARE BOUND BY > "THE >> BINDING PROBLEM"? >> >> Jim Bromer wrote: >>> Ed Porter said: >>> >>> It should be noted that Shruiti uses a mix of forward changing and >> backward >>> chaining, with an architecture for controlling when and how each is used. >>> ... >>> >>> My understanding that forward reasoning is reasoning from conditions to >>> consequences, and backward reasoning is the opposite. But I think what is >> a >>> condition and what is a consequence is not always clear, since one can > use >>> if A then B rules to apply to situations where A occurs before B, B > occurs >>> before A, and A and B occur at the same time. Thus I think the notion of >>> what is forward and backward chaining might be somewhat arbitrary, and >> could >>> be better clarified if it were based on temporal relationships. I see no >>> reason that Shruiti's "?" activation should not run be spread across all >>> those temporal relationships, and be distinguished from Shruiti's "+" and >>> "-" probabilistic activation by not having a probability, but just a >>> temporary attentional characteristic. Additional inference control >> mechanism >>> could then be added to control which directions in time to reason with in >>> different circumstances, if activation pruning was necessary. >>> >> >> This is not correct. >> >> Forward chaining is when the inference engine starts with some facts and >> then uses its knowledge base to explore what consequences can be derived >> from those facts. Going in this direction the inference engine does not >> know where it will end up. >> >> Backward chaining is when a hypothetical conclusion is given, and the >> engine tries to see what possible deductions might lead to this >> conclusion. In general, the candidates generated in this first pass are >> not themselves directly known to be true (their antecedents are not >> facts in the knowledge base), so the engine has to repeat the procedure >> to see what possible deductions might lead to the candidates being true. >> The process is repeated until it bottoms out in known facts that are >> definitely true or false, or until the knowledge base is exhausted, or >> until the end of the universe, or until the engine imposes a cutoff >> (this one of the most common results). >> >> The two procedures are quite fundamentally different. >> >> >> Richard Loosemore >> >> >> >> >> >>> Furthermore, Shruiti, does not use multi-level compositional hierarchies >> for >>> many of its patterns, and it only uses generalizational hierarchies for >> slot >>> fillers, not for patterns. Thus, it does not many of the general > reasoning >>> capabilities that are necessary for NL understanding.... Much of the >>> spreading >>> activation in a more general purpose AGI would be up and down >> compositional >>> and generaliztional hiearachies, which is not necessarily forward or >>> backward chaining, but which is important in NL understanding. So I agree >>> that simple forward and backward chaining are not enough to solve general >>> inferences problems of any considerable complexity. >>> >>> ----------------------------------- >>> Can you describe some of the kinds of systems that you think would be >>> necessary for complex inference problems. Do you feel that all AGI >>> problems (other than those technical problems that would be common to a >>> variety of complicated programs that use large data bases) are >>> essentially inference problems? Is your use of the term inference here >>> intended to be inclusive of the various kinds of problems that would >>> have to be dealt with or are you referring to a class of problems which >>> are inferential in the more restricted sense of the term? (I feel that >>> the two senses of the term are both legitimate, I am just a little >>> curious about what it was that you were saying.) >>> >>> I only glanced at a couple of papers about SHRUTI, and I may be looking >>> at a different paper than you were talking about, but looking at the >>> website it looks like you were talking about a connectionist model. Do >>> you think a connectionist model (probabilistic or not) is necessary for >>> AGI. In other words, I think a lot of us agree that some kind of >>> complex (or complicated) system of interrelated data is necessary for >>> AGI and this does correspond to a network of some kind, but these are >>> not necessarily connectionist. >>> >>> What were you thinking of when you talked about multi-level >>> compositional hierarchies that you suggested were necessary for general >>> reasoning? >>> >>> If I understood what you were saying, you do not think that activation >>> synchrony is enough to create insightful binding given the complexities >>> that are necessary for higher level (or more sophisticated) reasoning. >>> On the other hand you did seem to suggest that temporal synchrony spread >>> across a rhythmic flux of relational knowledge of might be useful for >>> detecting some significant aspects during learning. What do you think? >>> >>> I guess what I am getting at is I would like you to make some >>> speculations about the kinds of systems that could work with complicated >>> reasoning problems. How would you go about solving the binding problem >>> that you have been talking about? (I haven't read the paper that I >>> think you were referring to and I only glanced at one paper on SHRUTI >>> but I am pretty sure that I got enough of what was being discussed to >>> talk about it.) >>> >>> Jim Bromer >>> >>> ------------------------------------------------------------------------ >>> *agi* | Archives <https://www.listbox.com/member/archive/303/=now> >>> <https://www.listbox.com/member/archive/rss/303/> | Modify >>> <https://www.listbox.com/member/?&;> >>> Your Subscription [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/?&; >> 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/?&; > 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/?&; > 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=108809214-a0d121 Powered by Listbox: http://www.listbox.com
