The Importance of Consistency in Web Sites

Von Steve Telleen
Unternehmen investieren bedeutende Summen in Design und Funktionalität ihrer Websites. Trotzdem frustrieren sie vielfach ihre Besucher. Dabei kann schon die durchgängige Benutzerführung das Markenbewusstsein verstärken, argumentiert Steve Telleen, Analyst der Giga Group.

Many companies spend significant amounts of money on Web site design and functionality. Yet usability testing consistently shows that between half and three-quarters of the visitors on most Web sites leave without finding what they came for - even when it is on the Web site. If those expensive features on your Web site are being missed by half of the people looking for them, you are losing much of the value of your investment. In the virtual environment of a Web site, consistent landmarks, trail markers and signs provide the only definition of the landscape to guide your visitors. When common conventions are inconsistent with what the Web site visitor experiences, frustration levels mount. When the overall look and feel of the site is inconsistent, site branding does not occur and corporate branding is negatively affected. Companies need to provide the key consistency elements on their Web sites that support site visitor success, conventional expectations and branding. An analysis of 100 public Web sites audited by Giga's Web Site ScoreCardTM team in 2001, all belonging to large companies, showed that a significant number lacked consistency in even the most basic navigation elements. Forty-three percent of the sites did not have a logo with a link back to the home page on all their interior pages, and more than one-third of the sites did not have a text link to their home page on all their interior pages. One-third of the sites did not have consistent placement for global navigation links, and almost half did not have a consistent format for their global navigation. Nearly half of the sites lacked current location cues on their pages and more than one-third did not provide page titles in a consistent place with consistent fonts. Although direct studies proving the importance of Web site consistency are hard to find, there is plenty of indirect and circumstantial evidence that consistency is crucial for visitor satisfaction and success. Every book on Web site design stresses the importance of consistency. Most do not cite experimental studies, but base the case on common-sense approaches and analogy with other forms of communication and orientation. The following are the major benefits of consistency generally cited: Navigation efficiency Improved visitor satisfaction Confidence building (predictable landmarks) Brand reinforcement Design efficiency (designers can focus on unique content) There have been a few experimental studies on consistency; however, most predate the Web and deal with the more general case of consistency levels in PC-based software packages. These studies show that increasing the consistency levels of interfaces accomplished the following: Reduced error rates Reduced learning time Reduced task completion times Increased satisfaction We found only one study that contradicted this result. It partially supported the error rate results of earlier studies, but it did not support increased performance or satisfaction. However, this study was flawed from a Web navigation perspective because it measured only the performance on destination Web pages (clicking on text items, filling out forms, reading comprehension) rather than task-based activities that included finding the destinations. In fact, the navigation bars were disabled during the study. For more on the distinction between navigation and destination pages, see IdeaByte, Web Site Navigation Principles, Steve Telleen. An indirect reference to experimental data supporting user dissatisfaction with inconsistent Web navigation elements is found in Jakob Nielsen's Designing Web Usability. Nielsen says: "My usability studies show that users complain bitterly when a site tries to use navigation interfaces that are drastically different from the ones they have come to expect from the majority of other sites." Nielsen's observation brings up another aspect of consistency. Site visitors bring with them certain consistency expectations for Web sites in general. To support a good visitor experience, Web sites not only need to be internally consistent, but also consistent with the common conventions of all Web sites. For example, Michael Bernard of Wichita State University showed in experimental studies that the majority of Web site visitors have come to expect a link back to the home page in the upper left corner of every page on all Web sites and a help or support link in the upper right corner. Another conventional expectation of Web site visitors is that underlined text is a link. Even if a site is consistent in its use of underlining text that is not a link, most visitors will find the practice frustrating because it is not consistent with their expectations of how all Web pages are expected to behave. Two Analogies Supporting Consistency The first analogy supporting consistency comes from Jennifer Fleming's Web Navigation: Designing the User Experience: "It's the Hansel and Gretel factor: nobody likes to feel lost, and the quickest way to make someone feel lost and disoriented is to take away something they were relying on for direction. Sweep up the bread crumbs, and the fairy tale tykes are lost. Move or change the navigation scheme from screen to screen, and your users are lost." The second is one that Giga frequently uses in presentations: When the latest version of MicrosoftMicrosoft Office comes out, we dread moving to the new version. History strongly suggests that the toolbars and elements in the applications used most will be moved - inconsistent with what people are used to - and this is unsettling. They know it will take time to relearn the new layout and logic - time they don't have. Web site visitors face the same problem and have the same reaction when the key navigation and landmark elements change within the site. But on a Web site, the effect is amplified. It becomes equivalent to changing the application toolbar every time a new document is opened. Key Elements Elements that should be considered for consistency can be divided into three types: (1) those that improve visitor success, (2) those that meet conventional expectations and (3) those that support branding. The visitor success and conventional expectation elements, listed below, should be the minimal standards for any Web site. If there is a justifiable reason for violating the consistency of the visitor success elements, it is likely a business branding issue. In these cases, the inconsistent sites should be clearly separated and branded as different Web sites (see IdeaByte, Use Branding to Make Web Sites Consistent, Steve Telleen). The key elements that should be consistent for visitor success are: Site logo (usually the company logo) Global (site) navigation placement, format and fonts Global (site) navigation link names and destinations Subsite navigation placement, format and fonts Subsite navigation link names and destinations "Current location" indicator Page title placement, font, size and color Key elements consistent with conventional expectations are: Underlining should be used only for text links The logo should go in the upper left corner of every page The logo should be an active link to the site home page A home text link should be in the upper left corner of every page A help or support link should be in the upper right corner of every page Key elements where consistency supports branding are: Banner and page element shapes and colors Content layout and fonts Background and text colors Inconsistent navigation elements on a Web site waste the significant investments made in the functional destinations of the site and can lead to customer frustration and serious overall brand erosion for the company. The Web Site ScoreCard categories contain hundreds of elements known to affect visitor success and satisfaction. However, even a few simple, inexpensive steps, not requiring new technology, can dramatically improve navigation. Create and audit consistency standards for each Web site. At a minimum, include the visitor success and conventional expectation elements listed above. If there are good business reasons for supporting inconsistencies in the visitor success elements, the same business reasons also support creating separately branded Web sites. So, separate them.
Der Beitrag stammt aus dem aktuellen Research Digest der Giga Information Group. Alles zu Microsoft auf CIO.de

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