For large, complex site such as ours we need to consider Global, and Local navigation types and be consistent with the placement and use of each type.

Global: Site wide navigation enables vertical and lateral movement throughout the entire site
Local: Compliments the global navigation providing navigation specific to a section or sub-site

The most common and logical placement for the global navigation is horizontal navigation in the header.  The most common and logical placement for local navigation is left horizontal.  Left horizontal has the additional advantage that it can grow as the site grows and doesn’t require a redesign when space constraints are exceeded.

There are usability concerns related to creating both horizontal and vertical local navigation in addition to horizontal global navigation. Users can become overwhelmed and confused with too many menus.

A recent study published by Nielsen/Norman Group based on a study of college age students worldwide has quite a lot of information on navigation systems and the need to provide simple and predictable navigation on our websites.

Here’s a quote from one of the participants which sums up things nicely:

“It’s easier when the header is at the top with the search bar and the
different topics on the side [left navigation]. It’s what everyone’s been
using. It’s how our brain’s been programmed to work with the
computer. It might look neat with the other set up, but I like simple
much better.”

I purchased a site license of the report and you are welcome to share this link with any employee of Boise State
https://docs.google.com/a/boisestate.edu/viewer?a=v&pid=explorer&chrome=true&srcid=0B_SKcxGnEpjCNjIxMDQ5ZTMtY2NjOC00NWExLWE3MDMtY2ZlNThlNzUzYzMx&hl=en_US Boise State Login Required