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arXiv cs/0207083cs.AI
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Evaluating Defaults

Henry E. Kyburg, Choh Man Teng

摘要:

我们试图找到规范性标准的充分性非单调逻辑类似的标准的有效性演绎逻辑。我们不是规定一个推论的结论在前提为真的所有模型中为真,而是要求一个非单调推论的结论在前提为真的某种类型的“几乎所有”模型中为真。这种“某种”规范挑选出与推理相关的模型,考虑到诸如特异性和精确性以及先前的推理等因素。表征相关模型的频率反映了我们实际世界中的已知频率。默认推理的充分性标准可以通过阈值化扩展到扩展的充分性标准来扩展。我们表明,这避免了令人难以置信的,否则可能会导致连锁的默认推理。模型的比例,当解释的频率,提供了一个可验证的基础默认规则,并可以成为从统计数据生成默认规则的基础。

英文摘要:

We seek to find normative criteria of adequacy for nonmonotonic logic similar to the criterion of validity for deductive logic. Rather than stipulating that the conclusion of an inference be true in all models in which the premises are true, we require that the conclusion of a nonmonotonic inference be true in ``almost all'' models of a certain sort in which the premises are true. This ``certain sort'' specification picks out the models that are relevant to the inference, taking into account factors such as specificity and vagueness, and previous inferences. The frequencies characterizing the relevant models reflect known frequencies in our actual world. The criteria of adequacy for a default inference can be extended by thresholding to criteria of adequacy for an extension. We show that this avoids the implausibilities that might otherwise result from the chaining of default inferences. The model proportions, when construed in terms of frequencies, provide a verifiable grounding of default rules, and can become the basis for generating default rules from statistics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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