Contents Interface Design Introduction Basic interface design Access issues Navigation Links & navigation		Give users direct access The goal here is to provide the user with the information they want in the fewest possible steps, and in the shortest time. This means you must design an efficient hierarchy of information, to minimize the number of steps through menu pages. Interface studies have shown that users prefer menus that present a minimum of five to seven links, and that users prefer a few very dense screens of choices over many layers of simplified menus. In the table below note that you do not need many levels of menus to incorporate large numbers of choices: Bandwidth and interaction Users will not tolerate long delays. Human-factors research has shown that for most computing tasks the threshold of frustration is around 10 seconds. Web page designs that are not well "tuned" to the network access speed of your typical users will only frustrate them. If your users are primarily general public browsers "surfing" the Web via 28.8 kbps phone line connections it is foolish to put huge bitmap graphics on your pages the average user will not be patient enough to wait endlessly while your graphics download over the phone line. However, if you are building a university or corporate Intranet site where most users will be accessing your Web server at Ethernet speeds or better you can be much more ambitious in your use of graphics and multimedia. Simplicity and consistency Users are not impressed with complexity that seems gratuitous, especially users who may be depending on your site for timely and accurate work-related information. Your interface metaphors should be simple, familiar and logical to the audience if you want a metaphor for information design, choose a book or a library, not a spacecraft or a television set. The best information designs are the ones most users never notice. Studio Archetype's work for the Adobe Corporation site is an excellent model of Web site design. The pages use graphics extensively as navigation aids, consistently applied across every one of the pages in the site. Once you know where the standard links are on the page header graphics, the interface becomes almost invisible and navigation is easy. Graphic has been reduced from the original size.   www.adobe.com For maximum functionality and legibility your page and site design should be built on a consistent pattern of modular units, all sharing the same basic layout grids, graphic themes, editorial conventions, and hierarchies of organization. The goal is to be consistent and predictable, so that your users will feel comfortable exploring your site, and confident that they know how to find what they are looking for. The graphic identity of a series of pages in your Web site provides visual cues to the continuity of information. The header menu graphics present on every page of the Adobe site create a consistent user interface, and a consistent corporate identity: Graphic has been reduced from the original size.   www.adobe.com Even if your page uses no inlined graphics, a consistent approach to the layout of titles, subtitles, page footers, and navigation links to your home page or related pages will also reinforce the reader's sense of context within your site organization. To preserve the effect of a "seamless" system of pages you may want to consider bringing important information into your local site and adapt it to your page layout scheme rather than using links to send the reader away from your site (if there are no copyright restrictions on copying the information into your local site). Design stability If you want to convince your users that what you have to offer is accurate and reliable you will have to design your Web site just as carefully as you would any other type of corporate communication, with the same high editorial and design standards. A site that looks sloppily-built, with poor visual design and low editorial standards will not inspire confidence in your users. Functional stability in your Web design means keeping the interactive elements of your site working reliably. Functional stability has two components getting things right the first time as your design your site, and then keeping things functioning smoothly over time. Good Web sites are inherently interactive, with lots of links to local pages within the site, and links to other sites on the Web. As you create your design you will need to constantly check to be sure that all of your links work properly. things change quickly on the Web, both in your site and everyone else's. You will need to periodically check to be sure that your links are still working properly, and that the content they supply is still relevant to your needs. Feedback and dialog Your Web design should offer constant visual and functional confirmation of the user's whereabouts and options, via graphic design, navigation buttons, or uniformly-placed hypertext links. Feedback also means being prepared to respond to your user's inquiries and comments. Well-designed Web sites should always provide direct links to the site's editor or the "webmaster" responsible for running the site. Planning for this kind of on-going relationship with the users of your site is vital to the long-term success of the enterprise.
			Design for the disabled Not every user of your site will be able to take advantage of the graphics you offer on your pages, and a number of users may be visually impaired. One of the beauties of the Web and HTML is the ability to build in "alternate" messages ("ALT" tags in HTML) so that users without graphics capabilities can still understand the function of graphics on your pages. Using specially designed software, blind users can hear (via synthesized speech) the alternate messages you supply along with your graphics, and so will not completely miss the content of your pictures and graphic navigation buttons. If you will be using graphic menu systems for navigation, these text-based alternate menus will be an especially important aid to users without the ability to see your graphics. References Adobe Corporation. www.adobe.com Apple Computer, Inc. 1992. Macintosh human interface guidelines. Reading, MA: Addison-Wesley. Microsoft Corporation. 1995. The windows interface guidelines for software design. Redmond, WA: Microsoft Press. Shneiderman, B. 1992. Designing the user interface: Effective strategies for effective human-computer interaction. 2nd ed., Reading, Mass.: Addison-Wesley. Studio Archetype