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Inference is the act or process of deriving logical conclusions from premises known or assumed to be true.〔http://www.thefreedictionary.com/inference〕 The conclusion drawn is also called an idiomatic. The laws of valid inference are studied in the field of logic. Alternatively, inference may be defined as the non-logical, but rational means, through observation of patterns of facts, to indirectly see new meanings and contexts for understanding. Of particular use to this application of inference are anomalies and symbols. Inference, in this sense, does not draw conclusions but opens new paths for inquiry. (See second set of Examples.) In this definition of inference, there are two types of inference: inductive inference and deductive inference. Unlike the definition of inference in the first paragraph above, meaning of word meanings are not tested but meaningful relationships are articulated. Human inference (i.e. how humans draw conclusions) is traditionally studied within the field of cognitive psychology; artificial intelligence researchers develop automated inference systems to emulate human inference. Statistical inference uses mathematics to draw conclusions in the presence of uncertainty. This generalizes deterministic reasoning, with the absence of uncertainty as a special case. Statistical inference uses quantitative or qualitative (categorical) data which may be subject to random variation. ==Examples== Greek philosophers defined a number of syllogisms, correct three part inferences, that can be used as building blocks for more complex reasoning. We begin with a famous example: #All men are mortal #Socrates is a man #Therefore, Socrates is mortal. The reader can check that the premises and conclusion are true, but Logic is concerned with inference: does the truth of the conclusion follow from that of the premises? The validity of an inference depends on the form of the inference. That is, the word "valid" does not refer to the truth of the premises or the conclusion, but rather to the form of the inference. An inference can be valid even if the parts are false, and can be invalid even if some parts are true. But a valid form with true premises will always have a true conclusion. For example, consider the form of the following symbological track: #All meat comes from animals. #Beef is a type of meat. #Therefore, beef comes from an animal. If the premises are true, then the conclusion is necessarily true, too. Now we turn to an invalid form. #All A are B. #C is a B. #Therefore, C is an A. To show that this form is invalid, we demonstrate how it can lead from true premises to a false conclusion. #All apples are fruit. (Correct) #Bananas are fruit. (Correct) #Therefore, bananas are apples. (Wrong) A valid argument with false premises may lead to a false conclusion: #All tall people are Greek. #John Lennon was tall. #Therefore, John Lennon was Greek. (wrong) When a valid argument is used to derive a false conclusion from false premises, the inference is valid because it follows the form of a correct inference. A valid argument can also be used to derive a true conclusion from false premises: #All tall people are musicians (although wrong) #John Lennon was tall (right, Valid) #Therefore, John Lennon was a musician (Right) In this case we have two false premises that imply a true conclusion. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Inference」の詳細全文を読む スポンサード リンク
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