The phrase "authoritative medium" is correct and usable in written English.
It can be used to describe a source or channel of communication that is considered reliable and credible.
Example: "The report was published in an authoritative medium, ensuring that the information was trustworthy and well-researched."
Alternatives: "reliable source" or "trusted channel".
Speaking about writers specifically, the book is often assumed to be the most authoritative and important medium, but that's only because we've all been led to believe that (through a culture that has created The Myth about the author as authority).
Darker colors are more authoritative than medium or light shades.
Dean's pose screams "authoritative yet sensitive".
The stained-glass windows of Georges Braque, Jacques Villon, Georges Rouault, Marc Chagall, and Alfred Manessier are also noteworthy if less authoritative in their handling of the medium.
But if peace is made in the "minds of men," as the poet Archibald MacLeish said at the founding of UNESCO after World War II, the separation of authoritative knowledge from influence in a world where the social medium is not only the message, but the route to power, is a menacing turn for society.
On the other hand, no one has taken issue with his edits, only his assumed persona, so perhaps the real lesson of this democratic medium is that college drop-outs might be as authoritative as professors".
The meeting was convened on 30 March 2009 by then-head of the DPC Guido Bertolaso with the stated aim of providing authoritative information on a seismic "swarm" of small- and medium-sized tremors that had shaken the town over the previous 3 months.
That, of course, is an illusion, but the medium, apart from the genre of poetic experimental films, poses an immediate demand for authoritative representation that no other art is burdened by.
Authoritative! Hidebound!
