It is desirable to provide multiple ways to reach each page in the set of web pages, except for a series of processes, such as a page in the middle of a shopping cart. Many websites have a global menu, but in addition, if you have a site search, a link to a related page, a site map, or a index (page), you can meet this success criterion Regarding the "Index Page" way of thinking, you may need attention if that table of contents page is the only way to reach individual pages.)
Index page is a link list to each item hanging in a category, so to speak. Even if the site map is not complete (covering all pages), if you include a index page in the site map, you can say that you provided "multiple ways".
However, if the pages below the Table of Contents page are not reachable unless you click many times, implementation of site search will be good. Also, before you have such content, you should first make the structure of the site simple.
|Principle||Operable||User interface components and navigation must be operable.|
|Guideline||Navigable||Provide ways to help users navigate, find content, and determine where they are.|
|More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process.|