Literariness suggests a certain quality within texts that "makes of a given work a work of literature". The various literary devices that establish correspondences within literature are also prominent within language-based media art. Formalism was guided by the question of which attributes define literary or poetic language. Linguists as well as literary theorists have claimed that the idea of literariness as a poetic 'deviation' from standard language is relevant to both written and spoken texts —which is important when examining audiovisual artworks and their oral performances of literary aesthetics. Self-referentiality is also central to the theory of performativity. The ambiguity of poetic signs is grounded in the often indecisive tendency towards figural or literal signification. Irina Rajewsky fosters an understanding of intermediality "as a category for the concrete analysis of texts or other kinds of media products". For the purpose of investigations into 'medial configurations,' she proposes three subcategories: 'medial transposition,' 'media combination,' and 'intermedial references.'