Web Usability


The study of computing technology and user interfaces was initiated during the 1970s when industrial research laboratories began to focus on human-computer interaction (HCI) (Badre, 2002). In the 1980s, the personal computer was introduced, thus expanding the need for designing effective user interfaces. HCI became a discipline during this time, and the Association for Computing Machinery (ACM) established the Special Interest Group in Computer Human Interaction. One of the first text topics on HCI, Designing the User Interface: Strategies for Effective Human-Computer Interaction (Schneiderman, 19891), was published. Shortly thereafter, HCI became part of the ACM curriculum promoting the development of effective user interfaces. Software tools were developed in order to assist in designing usable interfaces while employing usability engineering methods. Many of these methods focused on usability from the perspective of ease of use, ease of learning, user satisfaction, and zero defects (Nielsen, 1993).
The World Wide Web (Web) became an integral part of HCI research in the 1990s, as organizations rushed to deploy a corporate Web site. Many of these Web sites took advantage of cutting-edge technology, including graphics and animation, with little regard for the impact on the user. As a result, users became disgruntled by lengthy download times, complex navigation schemes, nonintuitive search mechanisms, and disorganized content.
While others were predicting a “Y2K meltdown,” Jakob Nielsen (1999a) correctly predicted a “Web meltdown” due to the number of poorly designed Web sites that cluttered the Internet. Numerous studies showed that users were frustrated with glitzy Web sites that had too many usability barriers. A Forrester report estimated a 50% loss of potential online sales due to users not finding a product or service on the Web site (Manning, McCarthy & Souza, 1998). As importantly, 40% of users did not return to a site when their initial visit was a negative one.
Shortly after 2000, electronic commerce sites (dot coms) began to fail at an increasing rate. A Deloitte and Touche report found that many retailers had developed online sites to “test the waters” for consumer demand with no clearly articulated strategy for success (Speigel,2000). The demise of many dot coms has been attributed to unfriendly user interfaces that negatively impacted the online experience.


Many researchers and practitioners alike have studied usability in order to develop Web sites that are navigable, consistent, appealing, clear, simple, and forgiving of user mistakes (Murray & Costanza, 1999). Existing user interface design recommendations were extended to include user interfaces for the Web (Lynch & Horton, 1999; Schneiderman, 1998). Those experienced in designing user interfaces provided heuristics and guidelines for designing Web pages, often by identifying design layout, navigation, and performance issues associated with particular Web sites (Flanders & Willis, 1998; Hurst, 1999; Spool, Scanlon, Schroeder, Snyder & DeAngelo, 1999). Jakob Nielsen, a well-known usability expert, provided much needed guidance on Web usability through featured online articles (www.useit.com/alertbox) and published guidelines (Nielsen, 1999b; Nielsen & Tahir, 2002).
Web usability has been defined as the measure of the quality of the user’s online experience. There are several factors that are commonly used as a means of measuring this experience. These factors include (www.usability.gov):
• Learnability – A measure of the user’s learning time for accomplishing basic tasks given that the user interface has not previously been used (or used infrequently).
• Efficiency - A measure of the user’s time and error rate for task completion.
• Effectiveness - A measure of user productivity in performing a task.
• Satisfaction - A measure of the attitude, perceptions, and feelings about the site.
• Memorability - A measure of user recall such that a previously visited site can be used effectively with no new learning curve.
It is commonly accepted that the usability of a Web site is impacted by the user’s online goal, the user’s profile, and his or her computing environment. A user, for example, would have some tolerance for lengthy download times when searching for medical information with graphic illustrations. This tolerance level is greatly reduced when searching for information on the cost of an airline ticket. The user profile, including age, gender, income, education, computer skills, and other factors, influences the online experience. Web content written at a high reading grade level, for example, may be difficult to comprehend for users with low English proficiency. The use of color to convey meaning on a Web site may impede its use by those who have color-deficient sight. Small font size, patterned background images, and pastel colors may become Web barriers to older adults experiencing vision degradation due to aging (Morrell, 2002). The user’s computing environment also has an impact on Web usability. Environmental factors, such as hardware, software, browsers, connectivity, and bandwidth, impede the use of a Web site when it is cluttered with graphics, animation, and other objects adding little value to the online experience.
Since 1998, much has been accomplished in promoting Web usability for persons with disabilities. Section 508 of the 1973 Rehabilitation Act was enacted to eliminate information technology barriers in order to provide those with disabilities equal access. The law applies to all federal agencies when they develop, procure, maintain, or use electronic and information technology (http:// www.Section508.gov). As a result of this initiative, significant strides have been made to electronic government access by enforcing the Web content guidelines put forth by the World Wide Web Consortium. Though not mandated by law, many commercial and nonprofit Web sites have implemented Section 508 in order to provide access to a broad user base.


There are several popular methods that have been employed to effectively study Web usability. The inquiry approach makes use of field observation, interviews, self-reporting logs and online sessions. The inspection approach utilizes heuristic evaluations, walkthroughs, and checklists. Usability testing may also be used in conjunction with the other approaches to gather feedback during and after Web site design (Hom, 1998).
• Field Observation - The user is observed while surfing a Web site in order to gather usability data in a real-world setting.
• Interviews, Surveys, and Questionnaires - The objective of these methods is typically to gather feedback about the user’s perspective of usability. In terms of data gathering, the interview is a formal, structured process, whereas the survey is an informal, interactive process. Interviews and surveys may involve one or more users in a focus group setting. The questionnaire provides the means to obtain written responses regarding a user’s online experience.
• Session and Self-Reporting Logs - The user records his or her actions and makes observations during an online session. Software is often used during a session to automatically record data about the user’s online experience. The self-reporting log requires the user to manually record data while surfing the Web.

Table 1. Web usability online resources

Resource Description
http://www. usability.gov National Cancer Institute summarizes research activities on Web usability. It also provides links to usability resources.
http://www.itl.nist.gov/iad/vvrg/ind ex.html National Institute of Standards and Technology provides resources and tools for usability testing.
http://www. useit. com Jakob Nielsen and colleagues provide alert box articles, summaries of usability studies, and other usability resources.
http://www.acm.org/sigchi/ ACM Special Interest Group on Computer-Human Interaction provides a bibliography of usability research.
http://www.w3.org/WAI/ The World Wide Web consortium (W3C) Web initiative provides resources on making sites accessible to those with disabilities.
http://www. usabilitynews. org The Software Usability Research Laboratory (SURL) specializes in software and Web site user interface design research, human-computer interaction research, and usability testing and research.

• Heuristic Evaluation - A usability expert (or group of experts) assesses a user interface to determine whether the Web design follows established usability practices (heuristics).
• Walkthrough - A usability expert (or group of experts) evaluates online experiences by constructing scenarios of Web use and then role-playing the targeted user.
• Usability Inspection - A usability expert (or group of experts) conducts usability inspections of a user interface in order to uncover usability problems in the design.
• Checklists - A usability expert (or group of experts) uses a checklist often in conjunction with an inspection to ensure that established usability practices are evaluated.
• Usability Testing - Experiments are conducted regarding usability aspects of a Web design. The objective is to gather data about an online experience in order to draw conclusions about the usability of the site. Though usability testing can involve sophisticated technology including usability labs, videotaping, and eye-tracking, this does not have to be the case (Murray & Costanzo, 1999). Often, usability test cases can be generated from an existing Web design without the use of sophisticated technology.


There are valuable online resources promoting usable Web designs. Many of these sites offer links for usability design and testing, good practices and lessons learned in the field. Some of the more popular sources for Web usability guidance are listed in Table 1. Though too numerous to list, there are many educational sites that offer resources on research activities and course materials. The Trace Research and Development Center at the University of Wisconsin-Madision, in particular, offers usability resources and links promoting universal usability (http://trace.wisc.edu/world/web/).


Murray and Costanzo (1999) point out that from a HCI perspective, Web development is significantly different from software development. As such, there are challenges facing developers who are pursuing usable Web designs. These challenges include the following:
• The demographic diversity of online customers makes it difficult to develop user-friendly interfaces to meet all needs. For example, older adult users (60 years and older) may have trouble seeing Web content based on the use of color, font size, font type, and patterned background images (Becker, 2004; Morrell, Dailey, Feldman, Mayhorn & Echt, 2002). These design elements may have no usability impact on a younger adult for whom aging vision changes have not yet occurred. Web site images or textual references to religious holidays (e.g., Valentine’s Day), as another example, may be offensive in certain global regions due to local religious or cultural beliefs (Becker, 2002).
• There is significant diversity among hardware, software, and network components being used to surf the Web. The usability of mobile technology, for example, must take into account the tiny screen in which Web content is displayed (Russell & Chaparro,2002).
• Slower network access speeds impact usability due to performance degradation for a Web page with graphics and animation. Usability is also impacted by the browser version being used to surf the Web. Web content may display differently in older browser versions of Netscape© and Internet Explorer© than newer versions.
• The internationalization of many Web sites must account for culture, religion, and language in designing localized, user-friendly interfaces. Too often, organizations develop localized versions that do not meet the needs of regional customers (Marcus & Gould, 2000). The localized site may still have design aspects of the country of origin such as: English content, cliches, acronyms, and abbreviations (Becker & Mottay, 2001). Graphics may become a usability issue when cultural and religious beliefs are not taken into account during Web design (e.g., scantily clad figure on a homepage).
• Unlike software, users do not have a vested interest in a particular site. Often times, a user has purchased software and therefore is willing to accept usability barriers associated with it. Since there is no personal investment in a Web site, a user is more likely to leave and not return to a Web site that is perceived as unusable.


Web usability remains an important consideration in the design of effective user interfaces. There has been significant research on Web usability in terms of design layout,performance, navigation, and searches, among other areas. This initial work has been broadened to include usable Web designs for all users regardless of age, skills, education, culture, language, or religion. The Web accessibility initiative has promoted Web designs that take into account users with vision, physical, and cognitive disabilities. The internationalization of Web sites has promoted Web designs that meet the needs of a particular locale taking into account the customs, culture, religion, education, and other factors. Though much has been accomplished in developing usable Web sites, there is still work to be done. New technologies and expanded marketplaces pose unique challenges for universally usable Web designs.


Dot Com: A Web site that is intended for business use, though the term is commonly used to represent any kind of Web site. The term evolved from the “com” part of a Web site’s address, which represents commercial sites. It came to be associated with Internet companies that failed during the mid 2000s (www.searchWebservices.com).
Internationalization: It is the process of making a Web site interoperable in a specific market or locale. In general, interoperability means that the functionality of the site is not dependent on a specific language or culture and is readily adaptable to others.
Localization: It is the process of adapting an internationalized Web site to meet language, culture, religion, and other requirements of a specific market or locale.
Universal Usability: Universal usability can be defined as having more than 90% of all households as successful users of information and communications services at least once a week (Schneiderman, 2000, p. 85).
Usability: The ISO 9241-11 standard states that usability is the “effectiveness, efficiency and satisfaction with which a specified set of users can achieve a specified set of tasks in a particular environment”.
Usability Engineering: It is a systematic approach to making software (Web designs) easy to use, thus meet the needs of the targeted users.
Web Accessibility: Web accessibility means that any person, regardless of disabilities, is able to use Web technology without encountering any barriers.

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