The Social Interpretation of Language and Meaning. University Park Press, 1978.
Language consists of exchanges of meaning in various interpersonal contexts.
How these processes occur, for Halliday, can be seen in the work of Basil Bernstein, who has demonstrated how a culture's semiotic systems vary in their accessibility given different social groups, and in the work of William Labov, who has demonstrated how variation in the linguistic system expresses variation in social status and roles. Language both expresses and actively symbolizes social structures and systems. The perspective developed in Language as Social Semiotic originates, as Halliday explains, in the ethnographic-descriptive tradition in linguistics that includes Saussure, Hyelmslev, Mathesius and the Prague school, Malinowski, Firth, Boas, Sapir, and Whorf.