Abstract
Usability evaluation which refers to a series of activities that are designed to measure the effectiveness of a system as a whole, is an important step for determining the acceptance of system by the users. Usability evaluation is becoming important since both user groups, as well as tasks, are increasing in size and diversity. Users are increasingly becoming more informed and, consequently, have higher expectations from the systems. Moreover “system interface” has become a commodity and, hence, user acceptance plays a major role in the success of the system. Currently, there are various usability evaluation methods in vogue, like cognitive walkthrough, think aloud, claims analysis, heuristic evaluation, and so forth. However, for this study we have chosen heuristic evaluation because it is relatively inexpensive, logistically uncomplicated, and is often used as a discount usability-engineering tool (Nielsen, 1994). Heuristic evaluation is a method for finding usability problems in a user interface design by having a small set of evaluators examine an interface and judge its compliance with recognized usability principles. The rest of the chapter is organized as follows: we first look at the definition of e-learning, followed by concepts of usability, LCD, and heuristics. Subsequently, we introduce a methodology for heuristic usability evaluation (Reeves, Benson, Elliot, Grant, Holschuh, Kim, Kim, Lauber, & Loh, 2002), and then use these heuristics for evaluating an existing e-learning system, GETn2. We offer our recommendations for the system and end with a discussion on the contributions of our chapter.
TopBackground
Starting with an understanding of users, and proceeding in concert with software engineering, usability engineering promotes user success and satisfaction. In this section, we introduce principal concepts of Web site usability engineering.
Users
In the context of this chapter, users are people who interact with Web sites. The term user is restricted to the intended users of a Web site. It excludes usability engineers (UEs), the site’s providers, and others who have any stake in the Web site. Users of Web sites differ across many dimensions, for example, age, gender, technology experience, intellectual or aesthetic preferences, interaction styles, and abilities.
Usability
A definition of usability, from the International Organization for Standardization (ISO), underlies UEs’ focus on users’ needs and their goal of meeting users’ needs through usability engineering. ISO defines usability in specific contexts of use: efficiency, effectiveness, and user satisfaction (ISO, 1998). Efficiency and effectiveness are components of user success. Satisfaction is an equal factor for usability: Usability = user success + user satisfaction.
The ISO definition implies that usable software must be accessible to users with special needs. Accessibility is a subdomain of usability in which users have physical and/or cognitive disabilities. Accessibility enables people with disabilities to experience success and satisfaction with software to a degree comparable to that enjoyed by people without disabilities (W3C, 2005).
User Participation in Web Site Development
Usability engineering relies on close interaction with users at strategic points where their input is crucial. Techniques span the software development life cycle. Examples include focus groups, interviews, surveys, design discussions, and observing as users interact with prototype Web sites. Collection of human performance data is key to evaluating users’ success. Typical measures of human performance include accuracy and speed of task completion. These measures of user success complement, and often contrast with, self-reported ratings of user satisfaction.
Mental Models
From experiencing computers and Web sites, users build mental models, that is, psychological representations of the ways in which computers and Web sites work (Carroll, 1990; Johnson-Laird, 1983). Highly experienced users have mental models of different categories of Web sites, for example, entertainment and informational sites. Novice users, however, may not have differentiated their mental model of Web sites into unique categories. UEs help designers make user-interface design consistent with frequent users’ expectations from prior experience with other Web sites. This consistency helps novices develop expectations as a basis for forming mental models that will apply across other Web sites. This is not to imply, however, that all user groups will have congruent mental models. Realistically, the mental models of different users and user groups will have some commonalties, yet, at the same, time exhibit many individual differences.
User Interface
A user interface (UI) is software that people use to interact with technology. The UI encompasses more than what users see or hear. In the broadest sense, the UI is the virtual place where the user’s mental model meets the designers’ system model (Bolt, 1984.) Aligning these models is a goal of usability engineering (Norman & Draper, 1986).
Key Terms in this Chapter
Personas: Personas are archetypal users of an intranet or Web site that represent the needs of larger groups of users in terms of their goals and personal characteristics. They represent the real users and help guide the designers in making decisions about the system designs and functionalities. Personas represent behavior patterns by identifying user motivations, expectations, and goals from the system. Although personas are fictitious, they are based on knowledge and profiles of real users.
E-Learning: According to MSN Encarta, e-learning (or electronic learning) is “the acquisition of knowledge and skill using electronic technologies such as computer and Internet-based courseware, and local and wide area networks.” In other words, it is learning through electronic means where knowledge and skills are transferred either through the computer networks or through digital media like CD-ROM, DVDs, and so forth. In the Web environment, users may use virtual classrooms, digital collaboration, discussion forums, chat rooms, and so forth, to obtain information and facilitate learning.
User-Centered Design: It is a design approach in which the emphasis is on the users’ requirements and not on the designers’ capabilities. User-centered design helps achieve a high level of usability.
Usability: The ISO 9241 defines usability as “the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use.”
Heuristic Evaluation: Heuristic evaluation is a method for quick, cheap, and easy evaluation of a user interface design by comparing the system to a set of identified heuristics.
Learner-Centered Design: Learner-centered designs focus on developing a learner’s understanding, rather than on improving usability, of the designed system. In the context of e-learning systems, the focus is more on the achieving the “learning outcomes.”
Learnability: Learnability is defined as the ease and speed with which the users get familiar with the use of a new product. With high learnability, users can intuitively learn to use a product without training or manuals. However, in the context of e-learning, the definition of learnability includes the ability of users to effectively learn and retain the skills and knowledge.