Sidebar to Jakob Nielsen 's column on browser navigation features .

Here is a list of navigation support mechanisms that have been successful in earlier hypertext systems but are not found in current WWW browsers:

• Search (a real search, that is!)
• Overview diagram (global and local)
• Guided tours (paths)
• Tabletops (allowing some hypertext nodes to be seen simultaneously with others that they comment on; useful for educational hypertext)
• Fat links (open many destination nodes at once)
• Parameterized backtrack
• Visual cache
• Flying through the information space (and other ways of rapidly visualizing the main parts of the space)
• Link inheritance and clustering
• Time-dependent notation (breadcrumbs do age in current systems)
• Visual effects to emphasize navigational dimensions
• Pop-up links (visible in a spring-loaded mode without leaving the current page).
• Multi-lingual text-representation (as done in, e.g., Hyper-G - now renamed HyperWave)
• Posting relevance ratings with hypertext anchors (e.g., relevance from search or from community-based interest computation)
• Filtering of anchors

For more info about these features, see the navigation chapter in my book Multimedia and Hypertext: The Internet and Beyond .