Chapter 4. Designing Navigation Systems
Just wait, Gretel, until the moon rises, and then we shall see
the crumbs of bread which I have strewn about, they will show us our
way home again.
--Hansel and Gretel
As our fairy tales
suggest, getting lost is often a bad thing. It is associated with
confusion, frustration, anger, and fear. In response to this danger,
we have developed navigation tools to prevent people from getting
lost. From bread crumbs to compass and astrolabe to maps, street
signs, and global positioning systems, people have demonstrated great
ingenuity in the design and use of navigation tools.
We use them to chart our course, to determine our position, and to
find our way back. They provide a sense of context and comfort as we
explore new places. Anyone who has driven through an unfamiliar city
as darkness falls understands the importance that navigation tools
play in our lives.
On the Web, navigation is rarely a life or death issue. However,
getting lost in a large web site can be confusing and frustrating.
While a well-designed hierarchical organization scheme will reduce
the likelihood that users will become lost, a complementary
navigation system is often needed to provide context and to allow for
greater flexibility of movement within the site.
Navigation systems can be designed to support associative learning by
featuring resources that are related to the content currently being
displayed. For example, a page that describes a product may include
see also links to related products and services
(this type of navigation can also support a company's marketing
goals). As users move through a well-designed navigation system, they
learn about products, services, or topics associated to the specific
content they set out to find.
Any page on a web site may have numerous opportunities for
interesting see also connections to other areas
of the site. The constant challenge in navigation system design is to
balance this flexibility of movement with the danger of overwhelming
the user with too many options.
Navigation systems are composed of a variety of elements. Some, such
as graphical navigation bars and pop-up menus, are implemented on the
content-bearing pages themselves. Others, such as tables of contents
and site maps, provide remote access to content within the
organization structure. While these elements may be implemented on
each page, together they make up a navigation system that has
important site-wide implications. A well-designed navigation system
is a critical factor in determining the success of your web site.
4.1. Browser Navigation Features
When designing a navigation system, it
is important to consider the environment the system will exist in. On
the Web, people use web browsers such as Netscape Navigator and
Microsoft Internet Explorer to move around and view web sites. These
browsers sport many built-in navigation features.
Open URL allows direct access to any page on a
web site. Back and Forward
provide a bidirectional backtracking capability. The
History menu allows random access to pages
visited during the current session, and Bookmark
enables users to save the location of specific pages for future
reference. Web browsers also go beyond the Back button to support a
"bread crumbs" feature by color-coding hypertext links.
By default, unvisited hypertext links are one color and visited
hypertext links are another. This feature helps users understand
where they have and haven't been and can help them to retrace
their steps through a web site.
Finally, web browsers allow for a prospective view that can influence
how users navigate. As the user passes the cursor over a hypertext
link, the destination URL appears at the bottom of the browser
window, ideally hinting about the nature of that content (see Figure 4-1). If files and directories have been carefully
labeled, prospective view gives the user context within the content
hierarchy. If the hypertext link leads to another web site on another
server, prospective view provides the user with basic information
about this off-site destination.
Figure 4-1. In this example, the cursor is positioned over the Investor Info button. The prospective view window at the bottom shows the URL of the Investor Info page.
Much research, analysis, and testing has
been invested in the design of these browser-based navigation
features. However, it is remarkable how frequently site designers
unwittingly override or corrupt these navigation features. For
example, designers often modify the unvisited and visited link colors
with no consideration for the bread crumbs feature. They focus on
aesthetics, attempting to match link colors with logo colors.
It's common to see a complete reversal of the blue and purple
standard. This is a classic sacrifice of usability[5] for aesthetics and belies a
lack of consideration for the user and the environment. It's
like putting up a green stop sign at a road intersection because it
matches the color of a nearby building.
Given proper understanding of the aesthetic and usability issues, you
can in fact modify the link colors and create an intelligent
balance.[6] Unfortunately, this convention has been violated so
frequently, the standard may no longer be standard.
A second common example of inadvertently
disabling valuable browser navigation features involves prospective
view. Image maps have become a ubiquitous navigation feature on web
sites. The graphic navigation bar allows the aesthetically pleasing
presentation of navigation options. Unfortunately, server-side image
maps completely disable the prospective view feature of web browsers.
Instead of the destination URL preview, the XY coordinates of the
image map are presented. This information is distracting, not useful.
Again, a solution that balances aesthetics and usability is
available. Through an elegant use of tables (or by using client-side
image maps), you can present a graphical navigation bar that
leverages the browser-based prospective view feature.
Once you are sensitive to the built-in navigation features of web
browsers, it is easy to avoid disabling or duplicating those
features. In fact, it is both possible and desirable to find ways to
leverage them. In designing navigation systems, you should consider
all elements of that system. Web browsers are an extremely common and
integral part of the user's navigation experience. From a
philosophical perspective, we might say that web pages do not exist
in the absence of a web browser. So, don't override or corrupt
the browser!
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