Introduction to Semantics
Semantics is the study of meaning communicated through language. This tutorial is not introduction to SEO in practice and service, it is an introduction to the secret kernel of search engine and the other relevant theories - Semantic Theory, and it is not a SEO tutorial for beginners.
We begin with a basic assumption: that a person's linguistic abilities are based on knowledge that they have. It is this knowledge that we are seeking to investigate. One of the insights of modern linguistics is that speakers of a language have different types of linguistic knowledge, including how to pronounce words, how to construct sentences, and about the meaning of individual words and sentences. To reflect this, linguistic description has different levels of analysis. So phonology is the study of what sounds a language has and how these sounds combined into from words; syntax is the study of how words can be combined into sentences; and semantics is the study of the meanings of words and sentences.
The division into levels of analysis seems to make sense intuitively: if you are learning a foreign language you might learn a word from a book, know what it means but not know how to pronounce it. Or you might hear a word, pronounce it perfectly but not know what it means. Then again, you might know the pronunciation and meaning of, say a noun, but not know how its plural is formed or what its genitive case looks like. In this sense knowing a word unites different kinds of knowledge, and this is just as true of your knowledge of how to construct phrases and sentences.
Since linguistic description is an attempt to reflect a speaker's knowledge, the semanticist is committed to describing semantic knowledge. This knowledge allows English speakers to know, for example: the both the following sentences describe the same situation:
1.1 In the spine, the thoracis vertebrae are above the lumbar vertebrae.
1.2 In the spine, the lumbar vertebrae are below the thoracic vertebrae.
that 1.3 and 1.4 below contradict each other:
1.3 Addis Ababa is the capital of Ethiopia.
1.4 Addis Ababa is not the capital of Ethiopia.
that 1.5 below has several possible meanings, i.e. is ambiguous:
1.5 She gave her the slip.
that 1.6 below entails 1.7:
1.6 Henry murdered his bank manager.
1.7 Henry's bank manager is dead.
We will look at these types of semantic knowledge in more detail a little later on; for now we can take entailment to mean a relationship between sentences so that if a sentence A centrails a sentence B, then if we know A same time, to assert A and deny B. Knowing the effect of inserting the word not, or about the relationships between above and below, and murder and dead, are aspects of an English speaker's semantic knowledge, and thus should be part of a semantic description of English.
As our original definition of semantics suggests, it is a very broad field of inquiry, and we find scholars writing on very different topics and using quite different methods, though sharing the general aim of describing semantic knowledge. As a result semantics is the most diverse field within linguistics. In addition, semanticists have to have at least a nodding acquaintance with other disciplines, like philosophy and psychology, which also investigate the creation and transmission of meaning. Some of the questions raised in these neighbouring disciplines have important effects on the way linguists do semantics. In the next part of the tutorial we will discuss some of these question, but we begin in this part of the tutorial by looking at the basic tasks involved in establishing semantics as a branch of linguistics.