Usability engineering is a field that is concerned generally with human-computer interaction and specifically with devising human-computer interfaces that have high usability or user friendliness. It provides structured methods for achieving efficiency and elegance in interface design.
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Several broad disciplines including Psychology, Human Factors and Cognitive Science subsume usability engineering, but the theoretical foundations of the field come from more specific domains: human perception and action; human cognition; behavioral research methodologies; and, to a lesser extent, quantitative and statistical analysis techniques.
When usability engineering began to emerge as a distinct area of professional practice in the mid-to late 1980s, many usability engineers had a background in Computer Science or in a sub-field of Psychology such as Perception, Cognition or Human Factors. Today, these academic areas still serve as springboards for the professional practitioner of usability engineering, but Cognitive Science departments and academic programs in Human-Computer Interaction now also produce their share of practitioners in the field.
The term usability engineering (in contrast to interaction design and user experience design) implies more of a focus on assessing and making recommendations to improve usability than it does on design. However, Usability Engineers may still engage in design to some extent, particularly through the design of wire-frames or other prototypes.
Standards and guidelines
Usability engineers sometimes work to shape an interface such that it adheres to accepted operational definitions of user requirements documentation. For example, the International Organisation for Standardisation-approved definitions (see e.g., ISO 9241 part 11) usability are held by some to be a context-, efficiency, and satisfaction with which specific users should be able to perform tasks. Advocates of this approach engage in task analysis, then prototype interface design, and usability testing on those designs. On the basis of such tests, the technology is potentially re-designed if necessary.
The National Institute of Standards and Technology has collaborated with industry to develop the Common Industry Specification for Usability – Requirements, which serves as a guide for many industry professionals. The specifications for successful usability in biometrics were also developed by the NIST. Usability.gov provides a tutorial and wide general reference for the design of usable websites.
Usability, especially with the goal of Universal Usability, encompasses the standards and guidelines of design for accessibility. The aim of these guidelines is to facilitate the use of a software application for people with disabilities. Some guidelines for web accessibility are:
- The Web Accessibility Initiative Guidelines.
- The Section 508 government guidelines applicable to all public-sector websites.
- The ADA Guidelines for accessibility of state and local government websites.
- The IBM Guidelines for accessibility of websites.
Methods and tools
Usability Engineers conduct usability evaluations of existing or proposed interfaces and their findings are fed back to the designer for use in design or redesign. Common usability evaluation methods include:
Usability testing is when participants are recruited and asked to use the actual or prototype interface and their reactions, behaviors, errors, and self-reports in interviews are carefully observed and recorded by the Usability Engineer. On the basis of this data, the Usability Engineer recommends interface changes to improve usability. These studies can be either analytical or empirical.
There are a variety of online resources that make the job of the Usability Engineer a little easier. Some examples of these include:
This is a product of the National Institute of Standards and Technology. This toolkit is focused on evaluating the HTML of a website versus a wide range of usability guidelines and includes:
This tool is produced by Mind Design Systems is available freely to federal government employees. According to the official company website this tool consists of two tightly-integrated applications. The first is the UTE Manager, which helps a tester set up test scenarios (tasks) as well as survey and demographic questions. The UTE Manager also compiles the test results and produces customized reports and summary data, which can be used as quantitative measures of usability observations and recommendations.
The second UTE application is the UTE Runner. The UTE Runner presents the test participants with the test scenarios (tasks) as well as any demographic and survey questions. In addition, the UTE Runner tracks the actions of the subject throughout the test including clicks, keystrokes, and scrolling.
This tool is a product of UsableNet.com and implements the section 508 Usability and Accessibility guidelines as well as the W3C Web Accessibility Initiative Guidelines.
It is important to remember that online tools are only a useful tool, and do not substitute for a complete Usability Engineering analysis.