Before coding any part of a hypermedia computer-based training (CBT) system, designers need to decide how much control their users should have over their individual paths through the system. Designers can choose from three different levels of control within a hypermedia CBT system: complete computer control, complete user control, and adaptive computer control. Each level of control is suited to different types of audiences and system goals. Current research provides some guidelines for designers—showing which types of audiences and system goals are suited to which methods of control.
This article revisits three past articles about the implications of hypermedia in the 21st century. Each August, the ACM Journal of Computer Documentation reprints a classic article, book chapter, or report along with several analytical commen- taries and a response by the author of the classic document. In this context, a 'classic' document means one that was published at least five years ago but is no longer in print. It also means one that raises issues of lasting importance to the profession.
NoteCards, developed by a team at Xerox PARC, was designed to support the task of transforming a chaotic collection of unrelated thoughts into an integrated, orderly interpretation of ideas and their interconnections. This article presents NoteCards as a foil against which to explore some of the major limitations of the current generation of hypermedia systems, and characterizes the issues that must be addressed in designing the next generation systems.