We define interactivity as the degree to which users input choices or content. Besides the obvious interactivity offered by slide shows and polls, the ability for citizens to serve as sources of content – through blogs, forums, uploaded videos, etc. – represents another level of interactivity.
The challenge is how to include interactivity within a multimedia news story or presentation (i.e. college lecture) when the goals are engagement and learning. Too much interactivity, however, is counter productive. Although it’s been shown that users who control their navigation can learn more than users who don’t, too much interactivity inhibits comprehension by overwhelming the user’s working memory.
Regardless of the media used, or the face that some users claim they can multi-task, every user has limited cognitive capacity to engage with content. Consequently, interactivity alone does not guarantee learning of content. Our research pursues the right level of interactivity with different types of content.
Mayer & Chandler (2001)
Mayer, R., Dow, & Mayer, S. (2003)