It is not enough, technologically, to simply assemble the loose pieces, since data cannot be moved easily among them . . . A larger difficulty is the fact that each software system has its own file structure, which means that separate files must be maintained for each version of the data. Hence, a student’s work associated with a particular activity is stored in a collection of files depending on the applications used rather than on the nature of the educational activity. Similarly, each separate software system controls the screen when it is active, so if one application is active, then any other applications sharing the same screen space are hidden behind it, and vice-versa. These limitations drastically narrow or fracture educational activities. (p. 7).