Two excellent sources of information about interactivity are (a) Rod Sims ITForum paper [ITForum #10] entitled Interactivity: A Forgotten Art? and (b) Chapter 1, in Interactive Multimedia Instruction by Richard Schwier and Earl Misanchuk (published by Educational Technology Publications), which includes a Taxonomy of Multimedia Interactions.
If you are familiar with both of these and have found them to not be what you are looking for, please elaborate.