The first dimension, engagement,
refers to interactivity which is either navigational (where the user moves
from one location in the application to another) or instructional (where
the user is involved with the content in a way designed to facilitate learning).
The second dimension, control, refers to the extent to which the system
(program control) or user (learner control) is making the instructional
or navigational decisions. The third dimension, interactive concept, provides
an indication of the type of interaction which might be expected under
the varying conditions defined by the model.