In essence, the sitemap menu is simply an extension of the tree menu that appears the left inset on every webpage. However, the sitemap occupies its own page, which then allows the scope of information displayed to be expanded. In the following partial screen snapshot, we can directly compare the information in the tree and sitemap menus.
The extra page space associated with the sitemap allows an expanded description of each page, which aligns to the HTML page <h1> heading. In addition, a hierarchical section number is generated that make the sitemap more analogous to the content page(s) of a book.
So which menu mechanism should a user select?
Well, basically this is up to the user, but as suggested, the top menu may have some initial advantage when first entering the site, i.e. just to see the main topics via the drop-down menu. In contrast, the page menu become more useful when you a reading through a sequence of hierarchical pages, but it is not always clear where you are going or where you come from, which is a general problems with most informational websites. In this respect, the sitemap allows you to 'open/all' pages and then select any page within the hierarchy and then return on completion using either the browser <back-page> option or the <sitemap link> in the page menu.
What about the implementation?
<! start of #content div >
<div id="myContents" class="insetContent">
<img height="344" src="../images/pictures/413.treemap.jpg" width="265">
<p>See right insets for general instructions. </p>
<p>A link to the sitemap exists on the page navigation option available
in the top-left inset on every page. As such, you can use the sitemap
to access successive pages in order by linked back to the sitemap to
select the next page. </p>
While there are some additional features associated with the siteMap function in comparison to the treeMenu function, the fundamental mechanism of importance essentially replicates the description already given for the tree menu.