Medium theory is a mode of analysis that examines the ways in which particular communication media and modalities impact the specific content (messages) they are meant to convey. It Medium theory refers to a set of approaches that can be used to convey the difference in meanings of messages depending on the channel through which they are transmitted. Medium theorists argue that media are not simply channels for transmitting information between environments, but are themselves distinct social-psychological settings or environments that encourage certain types of interaction and discourage others.[1][2]
Moreover, this set of approaches focuses on the distinct affordances that a given medium may possess that affects the messages that are being conveyed through it.[2] The key assumption is that, rather than just being the means by which the communication takes place, media is a diverse set of environments that enable the communication to happen; as such, it may alter the meaning and sense of the information that is transferred through it. Accordingly, medium theory is distinct from the more generic 'media theory', the majority of which place its emphasis on the content of communication (e.g., sex and violence) rather than the medium.[3]: 305
Joshua Meyrowitz originated the term in his 1985 book, No Sense of Place. Meyrowitz used the term to refer to the body of literature that focuses on the technological aspects of media beyond their content. It aims to look beyond the content to the medium which reveals the key to its social impact.[2][3]: 305 Such works includes to those of Harold Innis, Marshall McLuhan, Walter Ong, Jack Goody, and Neil Postman, among others.
Currently, medium theory occupies a marginal position within American communication and media studies.[3]: 305 In Canada and elsewhere, the theory continues to inform studies that assess large-scale social changes that follow the adoption of a new medium.