A SYSTEMATIC-APPROACH TO OUTLINE MANIPULATION

The outline (table of contents) of a document provides users with a hi erarchical view of the document's logical structure. Outlines reflect a conceptual model and can serve as a cognitive aid in reading and wri ting hypertext. Outlines may have balance along three dimensions: skel etal, lexical, and semantic. When outlines contain balance, alternativ e views of the outline are readily imagined. Furthermore, hypertext sy stems can automatically generate alternative outlines with a modified, depth-first traversal of the hypertext links and nodes. Methods for b uilding and maintaining balanced outlines have been successfully used by writers. Readers are aware of the potential of balance and alternat ive outlines but lack strategies for utilizing them.