Acting together or in concert; unity of action(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "coactivity" in a sentence
"Media coactivity: Media multi-tasking involving simultaneous or alternating use of two or more media, especially where the media are synchronized or coordinated … or available in the same system1."
"CMCMC as a lens Focal phenomena: Communication, conversation, social interaction; media coactivity (multitasking) Peripheral phenomena: Collaboration Excluded phenomena:"
"Potential implications of CMCMC For media coactivity and how human attention moves among media content items For discourse processing For sociological theories of unintended consequences and user structuration of technologies For understanding human motivations for using new media (e.g., sociability, interaction) For convergent media interface design"