The degree to which a hypertext system supports varied navigation methods is a good indicator of its overall flexibility. The amount of support varies widely among available hypertext systems. To further complicate comparison, some may not automatically provide a tool, but instead allow for its construction using simpler elements or a scripting language. For instance, an index for a particular book may be built by simply listing all of the desired terms in a node titled "Index" and making them source anchors. However, this is a time-consuming task which an automatic indexing tool could eliminate.
Most hypertext packages implement a subset of the following navigation tools. Note that many of these features have been designed to meet the needs of researchers and pedagogues; even rudimentary navigation tools (such as a history or index) may be unnecessary in a fiction.
The need for adaptive, intelligent assistance in navigation becomes great as the complexity of the network increases. An expert system can provide help in constructing coherent reader-based narratives.
Hypertext system designers and authors must be aware of how the rhetorical devices of a hypertext network differ from paper text. This is most important when considering which navigation features to use (and how they will be implemented) as they greatly shape a reader's experience.
Navigation features are discussed in Bernstein's "The Bookmark and the Compass" and Nielsen's "The Art of Navigating Through Hypertext."