Decoding, in semiotics, is the process of interpreting a message sent by an addresser to an addressee. The complementary process – creating a message for transmission to an addressee – is called encoding.
All communication depends on the use of codes. When the message is received, the addressee is not passive, but decoding is more than simply recognising the content of the message. Over time, each individual in the audience develops a cognitive framework of codes which will recall the denotative meaning and suggest possible connotative meanings for each signifier. But the actual meaning for each message is context-dependent: the codified relations between the signifiers in the particular context must be interpreted according to the syntactic, semantic and social codes so that the most appropriate meaning is attributed (for labelling usages by reference to national characteristics, see Americanism).
Although the addresser may have a very clearly defined intention when encoding and wish to manipulate the audience into accepting the preferred meaning, the reality is not that of textual determinism. What is decoded does not follow inevitably from an interpretation of the message. Not infrequently, the addressees find different levels of meaning. Umberto Eco called this mismatch between the intended meaning and interpreted meaning aberrant decoding. This apparent failure of communication may result from the fact that the parties use different codes because they are of a different social class or because they have different training or ability, because they have different world views or ideologies, or because they are from different cultures. David Morley argues that the outcome of decoding will be influenced by pragmatic issues, i.e. whether:
Further, Umberto Eco suggests a distinction between closed texts which predispose a dominant interpretation and more open texts which may have latent meanings or be encoded in a way that encourages the possibility of alternative interpretations.