J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings of the First International Conference on the Principles of Knowledge Representation and Reasoning, pages 505-- 516, Toronto, May 1989. Morgan Kaufman.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....rationality postulates constitute a sound and complete axiom system for several classical model theoretic entailment relations under uncertainty measures on worlds. In detail, they characterize classical model theoretic entailment under preferential structures [51, 34] infinitesimal probabilities [1, 47], possibility measures [17] and world rankings [52, 31] They also characterize an entailment relation based on conditional objects [18] A survey of all these relationships is given in [6, 24] Mainly to solve problems with irrelevant information, the notion of rational closure as a more ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings KR-89, pages 505--516. Morgan Kaufmann, 1989.

....Lehmann, and Magidor [41] which constitute a sound and complete axiom system for several classical model theoretic entailment relations under uncertainty measures on worlds. They characterize classical model theoretic entailment under preferential structures [58, 41] infinitesimal probabilities [1, 54], possibility measures [19] and world rankings [59, 36] They also characterize an entailment relation based on conditional objects [20] A survey of all these relationships is given in [6, 26] Mainly to solve problems with irrelevant information, the notion of rational closure as a more ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings KR-89, pages 505--516. Morgan Kaufmann, 1989.

....reasoning is an example of reasoning with speci city. Like anything in the real world, speci city appears under many guises that can be the distinction between background knowledge and evidence [19] between necessary and contingent facts [8, 49] or between conditional probability and facts [37, 38], or also in the interactions between defaults, rst discussed in [45] This is re ected in numerous approaches to reasoning with speci city in the literature such as the approaches in [1, 5, 8, 10, 18, 19, 22, 34, 39, 37, 38, 41] At the heart of each approach is the notion of a default and a ....

.... [19] between necessary and contingent facts [8, 49] or between conditional probability and facts [37, 38] or also in the interactions between defaults, rst discussed in [45] This is re ected in numerous approaches to reasoning with speci city in the literature such as the approaches in [1, 5, 8, 10, 18, 19, 22, 34, 39, 37, 38, 41]. At the heart of each approach is the notion of a default and a mathematical treatment of defaults that accounts for speci city. Roughly the approaches to reasoning with speci city could be divided into priority based and conditional approaches. Priority based approaches to reasoning with ....

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J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings of the 1st International Conference on Knowledge Representation and Reasoning (KRR'89), pages 505-516, 1989.

....rationality postulates constitute a sound and complete axiom system for several classical model theoretic entailment relations under uncertainty measures on worlds. In detail, they characterize classical model theoretic entailment under preferential structures [55, 34] infinitesimal probabilities [1, 49], possibility measures [16] and world rankings [56, 31] They also characterize an entailment relation based on conditional objects [17] That these equivalences are not incidental is shown by Friedman and Halpern [22] who prove that many approaches are expressible as plausibility measures and ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings KR-89, pages 505--516. Morgan Kaufmann, 1989.

.... are purely qualitative in nature, such as qualitative probabilistic networks [Wellman, 1990] Also non probabilistic schemes have been proposed, each addressing a specific type of uncertainty, such as Dempster Shafer theory [Shafer, 1976] possibility theory [Zadeh, 1978] and non monotonic logics [Pearl, 1989]. Each of these schemes typically allows for en coding only a few types of information. A unifying principle that would allow combining the various types of information has been lacking so far, making it hard to utilize the variety of information available in prac tice. With the purpose of ....

Judea Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings of the First International Conference on Principles of Knowledge Representation and Reasoning, KR89, pages 505-516, Toronto, Ontario, Canada, May 1989.

....postulates constitute a sound and complete axiom system for several classical model theoretic entailment relations under uncertainty measures on worlds. More precisely, they characterize classical model theoretic entailment under preferential structures [85, 57] infinitesimal probabilities [1, 80], possibility measures [30] and world rankings [86, 48] Moreover, they characterize an entailment relation based on conditional objects [31] A survey of all these relationships is given in [8] We will use the notion of entailment to refer to these equivalent entailment relations. That their ....

....of z , z , and lex entailment in which we can explicitly characterize these preference relations through additional strength and priority assignments. We first describe the notions of consistency, entailment, and proper entailment. These notions go back to Adams [1] and Pearl [80]. We define them in terms of world rankings (see especially Geffner s work [41, 42] for the equivalence to the original definitions) A conditional knowledge base KB is consistent iff there exists a world ranking that is admissible with KB . It is inconsistent iff no such a world ranking ....

[Article contains additional citation context not shown here]

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proc. 1st International Conference on Principles of Knowledge Representation and Reasoning (KR-89), Toronto, Canada, pp. 505--516. Morgan Kaufmann, 1989.

....rationality postulates constitute a sound and complete axiom system for several classical model theoretic entailment relations under uncertainty measures on worlds. In detail, they characterize classical model theoretic entailment under preferential structures [50, 34] infinitesimal probabilities [1, 46], possibility measures [17] and world rankings [51, 31] They also characterize an entailment relation based on conditional objects [18] A survey of all these relationships is given in [6, 24] Mainly to solve problems with irrelevant information, the notion of rational closure as a more ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings KR-89, pages 505--516. Morgan Kaufmann, 1989.

....justification of the reasons behind them. This paper aims to take a step towards the development of such a general theory by extending an existing approach [8] that does have a well established foundation but which was previously limited in its applicability. The semantics for defaults [1,16], which exhibits the core behaviour cited above, is grounded in probability theory the most common tool for reasoning under uncertainty. The consequences of a set of defaults are those satisfied in all probability distributions compatible with that set. By selecting just one of those ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: a survey. In Knowledge Representation, pages 505--515, 1989.

....rationality postulates constitute a sound and complete axiom system for several classical model theoretic entailment relations under uncertainty measures on worlds. In detail, they characterize classical model theoretic entailment under preferential structures [74, 47] infinitesimal probabilities [1, 69], possibility measures [21] and world rankings [75, 39] They also characterize an entailment relation based on conditional objects [22] A survey of all these relationships is given in [9] Recently, Friedman and Halpern [28] showed that many approaches describe the same notion of inference, ....

Pearl, J.: 1989, `Probabilistic semantics for nonmonotonic reasoning: A survey'. In: Proceedings KR-89. pp. 505--516.

....of possible worlds, #(w) is a truth assignment to primitive propositions for each world w # W , and X can be viewed as a measure on W . Some examples of X include possibility measures [Dubois and Prade, 1991] # rankings [Goldszmidt and Pearl, 1996] parameterized probability distributions [Pearl, 1989] (these are sequences of probability distributions; the resulting approach is more commonly known as # semantics) and preference orders [Kraus et al. 1990; Lewis, 1973] Somewhat surprisingly, all of these approaches are characterized by the six axioms and inference rules, which have been ....

....(as would be expected, given the default) should not cause us to retract the default conclusion # 1 . The fact that the KLM properties characterize so many different semantic approaches has been viewed as rather surprising, since these approaches seem to capture quite different intuitions. As Pearl 1989 said of the equivalence between # semantics and preferential structures, It is remarkable that two totally different interpretations of defaults yield identical sets of conclusions and identical sets of reasoning machinery. Plausibility measures help us understand why this should be so. In ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: a survey. In Proc. KR '89, pages 505--516, 1989.

....postulates constitute a sound and complete axiom system for several classical model theoretic entailment relations under uncertainty measures on worlds. More precisely, they characterize classical model theoretic entailment under preferential structures [25, 18] infinitesimal probabilities [1, 24], possibility measures [10] and world rankings. They also characterize an entailment relation based on conditional objects [11] A survey of all these relationships is given in [3] Roughly speaking, coherence based probabilistic reasoning is reducible to modeltheoretic probabilistic reasoning ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings KR-89, pp. 505--516. 1989.

....and developed, based on the works about annotated logic [135, 93] and on the possible world semantics. Alternatively, probabilities can refer to the elements in the domain, and represent statistical knowledge. We do not discuss this approach here. For more information on this topic, see e.g. [117, 124, 22, 123]. In the possible worlds approach, a probability range can be assigned to each formula in the body and in the head of a rule, and can contain in its definition variables ranging over [0; 1] A suitable model theory and semantics is introduced for negation free probabilistic logic programs [119] ....

J. Pearl. Probabilistic Semantics for Nonmonotonic Reasoning: A Survey. In R. Brachman, H. Levesque, and R. Reiter, editors, Proceedings of the First International Conference on Principles of Knowledge Representation and Reasoning (KR'89), pages 505--516. Morgan Kaufmann, May 1989.

....can be traced back some 100 years, to the works of Boltzmann, Maxwell, Gibbs, and Planck, and has been introduced in its modern form by Jaynes [11] and Tribus [35] proved its efficiency in various fields of Physics, Statistics, Information Theory, Pattern Recognition, Signal Processing, etc. [1, 8, 11, 12, 13, 14, 18, 25, 32, 33, 34, 35, 38]. To be applied successfully, most of the known approaches to reasoning with uncertain and incomplete information require an extensive statistical knowledge (e.g. prior and posterior probabilities for Bayesian methods, basic probability assignment in Dempster Shafer theory [3, 4, 29] prior ....

Pearl, J. Probabilistic semantics for nonmonotonic reasoning: a survey. Proc. First Intl. Conf. on Principles of Knowledge Representation and Reasoning (Toronto, May 1989) Morgan Kaufmann, San Mateo, CA, 1989, 699-710.

....rationality postulates constitute a sound and complete axiom system for several classical modeltheoretic entailment relations under uncertainty measures on worlds. In detail, they characterize classical model theoretic entailment under preferential structures [69, 42] infinitesimal probabilities [1, 64], possibility measures [17] and world rankings [70, 34] They also characterize an entailment relation based on conditional objects [18] A survey of all these relationships is given in [7] Recently, Friedman and Halpern [24] showed that many approaches describe the same notion of inference, ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings KR-89, pages 505--516. Morgan Kaufmann, 1989.

....of Obs such that an explanation ff is preferred to fi if EP (ff; Obs) EP (fi; Obs) and prob(ff) prob(fi) or EP (ff; Obs) EP (fi; Obs) and prob(ff) prob(fi) Unfortunately, this approach leaves many pairs of competing explanations incomparable. 3 An approach adopted by many researchers [8, 9, 31, 63, 64, 66, 79, 82], called Most Probable Explanation (MPE) in [63] or Maximum A Posteriory (MAP) assignment in [8, 9, 79] is selecting an explanation expl possessing a highest probability given all the available knowledge, that is, maximizing the posterior probability prob(expljS [Obs) This approach is based on ....

Pearl, J., 1989, Probabilistic semantics for nonmonotonic reasoning: a survey. In Proceedings, First Intl. Conf. on Principles of Knowledge Representation and Reasoning, Toronto, Morgan Kaufmann, San Mateo, CA, 699--710.

.... is admissible with a conditional knowledge base (L; D) iff ( 1 for all 2 L, and ( 1 and ( for all defaults 2 D. A default ranking on D maps each d 2D to a nonnegative integer. 2. 2 Semantics for Conditional Knowledge Bases Semantics (Adams [1] and Pearl [21]) We describe the notions of consistency, entailment, and proper entailment in terms of world rankings. A conditional knowledge base KB is consistent iff there exists a world ranking that is admissible with KB . It is inconsistent iff no such a world ranking exists. A conditional ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings KR-89, pages 505--516, 1989.

....postulates constitute a sound and complete axiom system for several classical model theoretic entailment relations under uncertainty measures on worlds. More precisely, they characterize classical model theoretic entailment under preferential structures [85, 57] infinitesimal probabilities [1, 80], possibility measures [30] and world rankings [86, 48] Moreover, they characterize an entailment relation based on conditional objects [31] A survey of all these relationships is given in [8] We will use the notion of entailment to refer to these equivalent entailment relations. That their ....

....z , and lex entailment in which we can explicitly characterize these preference relations through additional strength and priority assignments. 3.2 Semantics We first describe the notions of consistency, entailment, and proper entailment. These notions go back to Adams [1] and Pearl [80]. We define them in terms of world rankings (see especially Geffner s work [41, 42] for the equivalence to the original definitions) A conditional knowledge base KB is consistent iff there exists a world ranking that is admissible with KB . It is inconsistent iff no such a world ranking ....

[Article contains additional citation context not shown here]

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proc. 1st International Conference on Principles of Knowledge Representation and Reasoning (KR-89), Toronto, Canada, pp. 505--516. Morgan Kaufmann, 1989.

....Parsons Extending the Maximum Entropy Approach This paper aims to take a step towards the development of such a general theory by extending an existing approach [8] which does have a well established foundation but which was previously limited in its applicability. The semantics for defaults [1,16], which exhibits the core behaviour cited above, is grounded in probability theory the most common tool for reasoning under uncertainty. The consequences of a set of defaults are those satisfied in all probability distributions compatible with that set. By selecting just one of those ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: a survey. In Knowledge Representation, pages 505--515, 1989.

....as subjective, we can simply say that whenever, intuitively, the agent is entitled to infer S from total evidence T , we are free to claim that the inference is warranted exactly because the agent is entitled to take the conditional probability of S given T to be high. A number of writers [ Pearl, 1992; Adams, 1986; Geffner and Pearl, 1990 ] have followed this line, but usually with the constraint that to justify acceptance, the conditional probability of S given T must be arbitrarily close to 1.0. Few who adopt the currency of subjective probability are willing to squander it on acceptance, ....

Judea Pearl. Probabilistic semantics for nonmonotonic reasoning. In Robert Cummins and John Pollock, editors, Philosophy and AI. MIT Press, 1992.

....such as the logic N [Del87] ffl entailment [Pea88] preferential entailment [KLM90] CT4O and CO [Bou94] among others. These conditional logics have a minimal set of properties that ought to be common to all non monotonic inference systems and that constitue, as has been suggested by Pearl [Pea89], a conservative core of non monotonic reasoning. The properties are related to the fact that these approaches: provide a more natural representation of defaults than the traditional formalisms, such as default logic [Rei80] autoepistemic logic [Moo85] or circumscription [McC80] do not ....

J. Pearl. Probabilistic Semantics for Nonmonotonic Reasoning: a Survey. In Proc. KR'89, pages 505-516, 1989.

....in the sense that for any formula OE, at least one of the necessity values N (OE) and N ( OE) is 0. We cannot have assertions that simultaneously support the necessity of a set of outcomes and its negation 6 . 4 The ffl in the threshold does not tend to 0, as in ffl semantics [Adams, 1975; Pearl, 1989], but is assumed to be fixed, although it can vary with context. 5 Note that a statement OE is taken to be false if Pr(OE) ffl, not if Pr(OE) 1 Gamma ffl. 6 This is the basic scenario. Possibility theory stems 4 SPECIFIC PARTITION SEQUENCES Now we show how the formalisms described in ....

Judea Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings of the First International Conference on Principles of Knowledge Representation and Reasoning, pages 505--516, 1989.

....certainly invalidate the inference P(Opus 2 Flying bird) 0:18 drawn earlier. It is necessary to emphasize that default reasoning about probabilities here is not seen as probabilistic extension of logical default reasoning, or as providing probabilistic semantics for logical default reasoning (cf. [Pea89]) Also one should be very cautious with equating default reasoning about probabilities with commonsense reasoning about probabilities, because it is not at all certain even that the latter really exists Different people s intuitions about which consequences to draw from probabilistic information ....

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings of the First International Conference on Principles of Knowledge Representation and Reasoning, pages 505--516, 1989.

No context found.

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings of the First International Conference on the Principles of Knowledge Representation and Reasoning, pages 505-- 516, Toronto, May 1989. Morgan Kaufman.

No context found.

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In Proceedings of the First International Conference on the Principles of Knowledge Representation and Reasoning, pages 505--516, Toronto, May 1989. Morgan Kaufman.

No context found.

J. Pearl. Probabilistic semantics for nonmonotonic reasoning: A survey. In R. J. Brachman, H. J. Levesque, and R. Reiter, editors, Proc. First International Conference on Principles of Knowledge Representation and Reasoning (KR '89), pages 505--516, 1989. Reprinted in Readings in Uncertain Reasoning, G. Shafer and J. Pearl (eds.), Morgan Kaufmann, San Mateo, CA, 1990, pp. 699--710.

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