The appearance of navigation plays a critical role in its perception and use. Background color, size, image positioning, and alignment can either cause or alleviate banner blindness, for instance. In turn, the visibility of navigation options can be the tipping point between meeting business goals and not. The graphic design of a site goes a long way in creating and reinforcing an online brand image, as well as the overall character of the site. Research shows that the single biggest factor influencing the credibility of a site is its visual appearance.
In terms of navigation, a primary consideration is whether to use plain HTML text or graphic images for menu options. Text-based links have many advantages over graphics because they:
Load faster than graphics
Can show visited link status by changing color
Are generally better for accessibility: screen readers have an easier time with text and users with poor eyesight can increase the font size
Can be easier to manage with content management systems
But graphics have a different quality and aesthetic than plain text. They can also create desired visual priorities and effects. The rounded corners of tabs, for instance, generally need to be created with images. Depending on the goals of the web site, graphics may be appropriate and necessary. Graphic images can:
Give a three-dimensional appearance to buttons and navigation bars
Make use of fonts that may not be installed on users' computers
Create rollover effects and other ...