Which one of the following has been considered as a non-specialist media…

Concept: In communication theory, thinkers who write about media are grouped by the discipline they work from. A specialist media thinker makes media and communication themselves the object of study and the institutional home of their career. A non-specialist media thinker arrives from some other discipline — sociology, economics, literature — and treats media as one component inside a wider theory of society. The label marks disciplinary origin and scope, not influence or importance.

Application: David Holmes applies exactly this term in Communication Theory: Media, Technology and Society (SAGE, 2005), where he writes of non-specialist media thinkers such as Manuel Castells, and the exam wording is drawn from that passage. Castells is a sociologist: his three-volume work The Information Age (1996-98) develops the idea of the network society, in which media and information technology appear as one strand alongside economy, identity and social movements. Media are the material of his social theory rather than his discipline, so Manuel Castells is the non-specialist media thinker.

Cross-check: The other three names sit differently on the same scale:

• Marshall McLuhan came to the subject from English literature, but media themselves are the entire object of Understanding Media (1964) and of the Centre for Culture and Technology he founded; Holmes sets Castells's argument against McLuhan's rather than placing the two in one category.

• Wilbur Schramm built communication into a university discipline: the first doctoral programme in mass communication at Iowa, then the Institute of Communications Research he founded at Illinois in 1947 and the Institute for Communication Research at Stanford in 1955, together with the field's early textbooks.

• George Gerbner directed the Cultural Indicators project at the Annenberg School for Communication, producing cultivation theory from inside a communication faculty.

The non-specialist media thinker among these four is therefore Manuel Castells.