Semantics

Definition
Semantics (Greek sēmantikos, giving signs, significant, symptomatic meaning, from sēma (σῆμα), sign) refers to aspects of meaning, as expressed in language or other systems of signs. As discussed in semiotics, the theory of signs, particularly in their International Encyclopedia of Unified Science, the field breaks out into three branches:


 * **Semantics**: Relation between signs and the things they refer to, their denotata.
 * **Syntactics**: Relation of signs to each other in formal structures.
 * **Pragmatics**: Relation of signs to their impacts on those who use them.

Semantics and Syntax
Semantics contrasts with syntax, which is the study of the structure of sign systems (focusing on the form, not meaning). When analyzing languages, an analysis can be said to cover both the "syntax and semantics" concerning both the format and meanings of phrases in a language. The term semantics can apply not only to natural languages, such as English, German or Latin, but also to technical languages, such as a computer programming language.

Pragmatics
Related to semantics is the field of pragmatics, which studies the practical use of signs by agents or communities of interpretation within particular circumstances and contexts.[1] By the usual convention that calls a study or a theory by the name of its subject matter, semantics may also denote the theoretical study of meaning in systems of signs.

Semanticists generally recognize two sorts of meaning that an expression (such as the sentence, "John ate a bagel") may have: **1)** the relation that the expression, broken down into its constituent parts (signs), has to things and situations in the real world as well as possible worlds, and **2)** the relation the signs have to other signs, such as the sorts of mental signs that are conceived of as concepts.

Denotation/Connotation
Most theorists refer to the relation between a sign and its objects, as always including any manner of objective reference, as its denotation. Some theorists refer to the relation between a sign and the signs that serve in its practical interpretation as its connotation, but there are many more differences of opinion and distinctions of theory that are made in this case. Many theorists, especially in the formal semantic, pragmatic, and semiotic traditions, restrict the application of semantics to the denotative aspect, using other terms or completely ignoring the connotative aspect.

Words, Structure and Memory
In psychology, //semantic memory// is memory for meaning, in other words, the aspect of memory that preserves only the gist, the general significance, of remembered experience, while //episodic memory// is memory for the ephemeral details, the individual features, or the unique particulars of experience.

Word meaning is measured by the company they keep; the relationships among words themselves in a //semantic network//. In a network created by people analyzing their understanding of the word (such as [|Wordnet]) the links and decomposition structures of the network are few in number and kind; and include "part of", "kind of", and similar links.

In automated ontologies the links are computed vectors without explicit meaning. Various automated technologies are being developed to //compute the meaning of words:// latent semantic indexing and support vector machines as well as natural language processing, neural networks and predicate calculus techniques.