Semiotics of Multimedia: Intro is a text book on the theory of multimedia by Bo Fibiger for courses at Aarhus University in Denmark. Excellent overview of definitions and theory.
A quote in the section on defintions:
“”Multimedia is the combination of time-based media – such as voice, animation, and video – along with space-based media – such as text, graphics, and images.”
(Christine Hughes/91)”
The major sections cover theory, production, visualization, narration and interaction, and copyright. The text seems aimed at producers to give them a theoretical framework.