Abstract
In the last years, Web systems have evolved from a simple collection of hypertext pages toward applications supporting complex (business) applications, offering (rapidly changing) information and functionality to a highly diversified audience. Although it is still easy to publish a couple of pages, it is now recognized that appropriate Web design methods are needed to develop more complex Web sites and applications (generally called Web systems). In the past, Web systems were created opportunistically without prior planning or analysis, and without any regard for methodology, resulting in Web systems that were lacking consistency in structure, navigation, and presentation, and were not transparent. A lot of these systems were also suffering from the classical maintenance problems and development backlog. In the same period, Web technology evolved at an equally dazzling rate enabling more advanced Web applications, but with the unfavorable consequence that Web development is no longer simple and easy. The latest developments in the field of the Web are related to the vision of the Semantic Web: an extension of the current Web in which information is given well-defined meaning, better enabling computers, and people to work in cooperation (Berners-Lee, Hendler, & Lassila, 2001). Together with the Web, a new problem unknown in classical information systems emerged: competition for the visitor’s attention. Especially for commercial Web systems, it is important to hold the interest of the visitors and to keep them coming back. As stated by usability expert Nielsen (2000, p. 9), “all the competitors in the world are but a mouse click away.” Much more than in “classical” software systems, the usability of Web systems is a primary factor for their success.
TopBackground
One way to deal with the usability of a Web system is by assessing the usability once the system is built and improving it if necessary. The techniques for accessing the usability of a Web system are mainly the same as those used in usability testing of classical user interfaces, for example, heuristic evaluation, expert-based evaluation, experimental evaluation, interviews, questionnaires, and so forth (Nielsen & Mack, 1994). Also, different tools are developed that support assessing the usability of Web sites (e.g., WebQuilt [Hong, Heer, Waterson, & Landay, 2001; Vanderdonckt, Beirekdar, & Noirhomme-Fraiture, 2004], and the full-featured experimentation environment of Noldus [www.noldus.com]). Another approach to enhance usability (and complementary to the first approach) is to use a Web design method that ensures a higher usability. The first Web design methods, HDM (Garzotto, Paolini, & Schwabe, 1993) and its successors HDM2 (Garzotto, Paolini, & Mainetti, 1993) and OOHDM (Schwabe & Rossi, 1995), and RMM (Isakowitz, Stohr, & Balasubramanian, 1995), were originally designed for hypertext applications or came from the database research community. These methods used database design methods like E-R (Chen, 1976) or OMT (Rumbaugh, Blaha, Premerlani, Eddy, & Lorensen, 1991), and focused on the organization of the data to be presented on the Web. These methods could solve to some extent maintenance problems, but they did not address usability. Essential for achieving a good usability in Web systems is meeting the needs of the (different) visitors. WSDM was one of the first Web design method to recognize this. This method was presented at the WWW7 conference (1998) as a “user-centered” design method for Web sites (De Troyer & Leune, 1998). The starting point in the approach is the set of potential visitors (audiences) of the Web system. The method recognizes that different types of visitors have different needs and that this should drive the design of the Web system rather than the organization of the available data. Later on (De Troyer, 2001), the authors renamed their approach from “user-centered” to “audience-driven,” to avoid confusion with the term “user-centered” from the HCI (human-computer interaction) field. In HCI, a user-centered approach refers to a design process in which users are actively involved (by interviews, scenario analysis, prototyping, evaluation, etc.). This explicit involvement is not necessary in WSDM. On the contrary, the individual Web users are unknown during the Web development process; they cannot be interviewed in advance, and they cannot be involved in the development process. In the audience-driven approach as defined by WSDM, the users play a central role, but it is not necessary to involve them actively in the development process.
Key Terms in this Chapter
Accessibility: People with disabilities can perceive, understand, navigate, and interact with the Web, and they can contribute to the Web.
Localization: In Web design and software, localization refers to the adaptation of language, content, and design to reflect local cultural sensitivities.
Usability: The extent to which a product or system can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use.
Context-Awareness: Property of devices or systems that have information about the circumstances under which they operate and can react accordingly. Context-aware systems may also try to make assumptions about the user’s current situation (also called personalization).