Summary

As much as it is possible to generalize, here is what seem to be the most important and effective elements of a navigable site:

• Well-defined site structure
• Clearly-visible navigation paths and low "link noise"
• A top-level navigation bar
• Coherent margin indexes
• An explicit location bar
• Consistency of navigation labels, appearance, and positioning on the page
• A well-marked start-to-end trail through documents
• Full contents listing in documents