Semiotics (also called semiotic studies or semiology) is the study of sign processes (semiosis), or signification and communication, signs and symbols, both individually and grouped into sign systems. It includes the study of how meaning is constructed and understood. One attempt to formalize the field was notably led by the Vienna Circle and presented in their International Encyclopedia of Unified Science, in which the authors agreed on breaking the field, which they called "semiotic", 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.

Semiotics is frequently seen as having important anthropological dimensions, for example Umberto Eco proposes that every cultural phenomenon can be studied as communication. However, some semioticians focus on the logical dimensions of the science. They examine areas belonging also to the natural sciences - such as how organisms make predictions about, and adapt to, their semiotic niche in the world (see semiosis). In general, semiotic theories take signs or sign systems as their object of study: the communication of information in living organisms is covered in biosemiotics or zoosemiosis.

Syntactics is the branch of semiotics that deals with the formal properties of signs and symbols. More precisely, syntactics deals with the "rules that govern how words are combined to form phrases and sentences.". Charles Morris adds that semantics deals with the relation of signs to their designata and the objects which they may or do denote; and, pragmatics deals with the biotic aspects of semiosis, that is, with all the psychological, biological, and sociological phenomena which occur in the functioning of signs.

The importance of signs and signification has been recognized throughout much of the history of philosophy, and in psychology as well. Plato and Aristotle both explored the relationship between signs and the world, and Augustine considered the nature of the sign within a conventional system. These theories have had a lasting effect in Western philosophy, especially through Scholastic philosophy. More recently, Umberto Eco, in his Semiotics and philosophy of language, has argued that semiotic theories are implicit in the work of most, perhaps all, major thinkers.

Current Applications of Semiotics

Some current applications of semiotics include:

• It represents a methodology for the analysis of texts regardless of modality. For these purposes, "text" is any message preserved in a form whose existence is independent of both sender and receiver;

• It can improve ergonomic design in situations where it is important to ensure that human beings can interact more effectively with their environments, whether it be on a large scale, as in architecture, or on a small scale, such as the configuration of instrumentation for human use.

Semiotics is only slowly establishing itself as a discipline to be respected. In some countries, its role is limited to literary criticism and an appreciation of audio and visual media, but this narrow focus can inhibit a more general study of the social and political forces shaping how different media are used and their dynamic status within modern culture. Issues of technological determinism in the choice of media and the design of communication strategies assume new importance in this age of mass media. The use of semiotic methods to reveal different levels of meaning and, sometimes, hidden motivations has led some[who?] to demonise elements of the subject as Marxist, nihilist, etc. (e.g. critical discourse analysis in Postmodernism and deconstruction in Post-structuralism).