Shannon laid the digital theoretical foundation of communication in the early 1940s. Shannon's law is a classical law about channel capacity calculation, which can be said to be the basis of information theory.
Shannon theory defines the relationship between the maximum transmission rate of a channel with random thermal noise and the channel bandwidth and signal-to-noise ratio. From the perspective of natural science, Shannon theory uses mathematical formulas to measure information flow (bits).
It has typical engineering significance. Because of Shannon's status as a scientist and research field, Shannon's theory and related theories focus not on the meaning of information expression, but on the effective transmission and reception of information.
Shannon distinguishes three levels of information dissemination in the paper: how to accurately transmit the communication symbols of layer A (technical problems); How can the symbols issued by layer B accurately convey the intended meaning (semantic problem)? How the accepted meaning of layer C can effectively affect behavior (effect or behavior problem) in the expected way.
Interestingly, Shannon repeatedly stated that the information theory he founded only dealt with layer A, and warned the academic circles not to apply this theory to all types of information communication theories.
Because the relationship between people or between people and society is far more complicated than that between people and machines or between machines. The layers B and C that Shannon doesn't want to deal with seem to be closer to the communication theory based on social humanities.
Stuart Hall, a British communication scholar in the post-Shannon era, interprets the state and effect of TV discourse communication in the article "Coding and Decoding of TV Discourse" published in 1973.
In the process of encoding the meaning of TV discourse, the production and circulation of TV discourse can be divided into three stages: the first stage, media workers process raw materials, that is, process or create the meaning of TV discourse, which Hall calls "encoding" stage.
Media workers are specially trained and studied. When coding, what is important is his world outlook, knowledge structure and special technical level.
Hall believes that raw materials contain cultural codes, which are natural, neutral and conventional. They have already integrated into the social structure of people's lives, and the process of coding is the significance of media workers releasing codes from a certain cultural perspective.