"A learning activity has a certain internal structure, binding together the characteristics generated by the analytical process of comparison. The internal structure will have a form that could also have existence in a computational form, such as a generic, customisable shell. An analogy would be Microsoft's Powerpoint programme. It has an internal structure that sequences slides, which are themselves customisable by the teacher. The programme is a very restricted form of learning activity model for a purely presentational form of teaching. The internal structure is important, because it defines how the characteristics work together. In the case of Powerpoint, it restricts what can count as a slide. A better shell would allow the teacher to incorporate Flash animations, for example."
(Diana Laurillard, 2002)
