Usability engineering
Encyclopedia
Usability engineering is a field that is concerned generally with human-computer interaction and specifically with making human-computer interfaces that have high usability
or user friendliness. In effect, a user-friendly interface is one that allows users to effectively and efficiently accomplish the tasks for which it was designed and one that users rate positively on opinion or emotional scales. Assessing the usability of an interface and recommending ways to improve it is the purview of the Usability Engineer. The largest subsets of Usability Engineers work to improve usability of software graphical user interface
s (GUIs), web-based user interfaces, and voice user interfaces
(VUIs).
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, though Usability Engineers may still engage in design to some extent, particularly design of wire-frames or other prototypes.
part 11) usability
are held by some to be a context-dependent yardstick for the effectiveness, 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 (ideally) re-designed or (occasionally) the operational targets for user performance are revised. [Dillon, 2000].
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
. Some primary guidelines for web accessibility are:
Usability testing
, the gold standard, 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.
There are a variety of online resources that make the job of the Usability Engineer a little easier. Some examples of these include:
1. The Web Metrics Tool Suite 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:
2. The Usability Testing Environment (UTE) produced by Mind Design Systems is available freely to federal government employees. According to the official company website this tool
3. The UsableNet Liftmachine 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.
, Jakob Nielsen
, and John M. Carroll
. Nielsen and Carroll have both written books on the subject of usability engineering. Nielsen's book is aptly titled Usability Engineering, and was published in 1993. Carroll wrote "Making Use: Scenario-Based Design of Human-Computer Interactions" in 2000, and co-authored "Usability Engineering: Scenario-Based Development of Human-Computer Interaction" with Mary Beth Rossen in 2001. Some other field leaders are Alan Cooper, Larry Constantine
and Steve Krug the author of "Don't Make Me Think! A Common Sense Approach to Web Usability".
There are many books written on Usability Engineering. A few of the more popular recently published books are as follows:
1. 1993 - Usability engineering by Jakob Nielsen - 362 pages
2. 1999 - Web site usability: a designer's guide by Jared M. Spool, Tara Scanlon - 157 pages
3. 1999 - The Usability Engineering Lifecyle: A Practitioner's Handbook by Deborah J. Mayhew - 542 pages
4. 2000 - Usability Engineering by Xristine Faulkner - 244 pages
5. 2001 - Usability Evaluation and Interface Design: Cognitive Engineering ... by Michael James Smith, Richard John Koubek, Gavriel Salvendy, Don Harris - 1592 pages
6. 2002 - Usability engineering: scenario-based development of human-computer interaction by Mary Beth Rosson, John Millar Carroll - 422
7. 2003 - The human-computer interaction handbook: fundamentals, evolving technologies ... by Julie A. Jacko, Andrew Sears - 1277 pages
8. 2007 - Usability Engineering: Process, Products, and Examples by Laura M. Leventhal, Julie Barnes - 314 pages
9. 2008 - Adoption-centric Usability Engineering: Systematic Deployment, Assessment ... by Ahmed Seffah, Eduard Metzker - Computers - 450 pages
10. 2008 - The Human-Computer Interaction Handbook: Fundamentals, Evolving Technologies ... by Andrew Sears, Julie A. Jacko - 1358 pages
11. 2011 - Usability Engineering and E-Health In (Editors Martina Ziefle, Carsten Rocker) Human-Centred Design of E-Health Technologies, IGI Global, pp. 46-64, ISBN 1-60960-177-7 .
Usability
Usability is the ease of use and learnability of a human-made object. The object of use can be a software application, website, book, tool, machine, process, or anything a human interacts with. A usability study may be conducted as a primary job function by a usability analyst or as a secondary job...
or user friendliness. In effect, a user-friendly interface is one that allows users to effectively and efficiently accomplish the tasks for which it was designed and one that users rate positively on opinion or emotional scales. Assessing the usability of an interface and recommending ways to improve it is the purview of the Usability Engineer. The largest subsets of Usability Engineers work to improve usability of software graphical user interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
s (GUIs), web-based user interfaces, and voice user interfaces
Voice User Interface
A Voice–user interface makes human interaction with computers possible through a voice/speech platform in order to initiate an automated service or process....
(VUIs).
Several broad disciplines including Psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
, Human Factors
Human factors
Human factors science or human factors technologies is a multidisciplinary field incorporating contributions from psychology, engineering, industrial design, statistics, operations research and anthropometry...
and Cognitive Science
Cognitive science
Cognitive science is the interdisciplinary scientific study of mind and its processes. It examines what cognition is, what it does and how it works. It includes research on how information is processed , represented, and transformed in behaviour, nervous system or machine...
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
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
or in a sub-field of Psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
such as Perception
Perception
Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...
, Cognition
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
or Human Factors
Human factors
Human factors science or human factors technologies is a multidisciplinary field incorporating contributions from psychology, engineering, industrial design, statistics, operations research and anthropometry...
. 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
Interaction design
In design, human–computer interaction, and software development, interaction design, often abbreviated IxD, is "the practice of designing interactive digital products, environments, systems, and services." Like many other design fields interaction design also has an interest in form but its main...
and user experience design
User experience design
User experience design is a subset of the field of experience design that pertains to the creation of the architecture and interaction models that affect user experience of a device or system...
) implies more of a focus on assessing and making recommendations to improve usability than it does on design, though Usability Engineers may still engage in design to some extent, particularly 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. For example, the International Organisation for Standardisation-approved definitions (see e.g., ISO 9241ISO 9241
ISO 9241 is a multi-part standard from the International Organization for Standardization covering ergonomics of human-computer interaction. It is managed by the ISO...
part 11) usability
Usability
Usability is the ease of use and learnability of a human-made object. The object of use can be a software application, website, book, tool, machine, process, or anything a human interacts with. A usability study may be conducted as a primary job function by a usability analyst or as a secondary job...
are held by some to be a context-dependent yardstick for the effectiveness, efficiency and satisfaction with which specific users should be able to perform tasks. Advocates of this approach engage in task analysis, then prototype
Software prototyping
*Software prototyping, refers to the activity of creating prototypes of software applications, i.e., incomplete versions of the software program being developed...
interface design, and usability testing
Usability testing
Usability testing is a technique used in user-centered interaction design to evaluate a product by testing it on users. This can be seen as an irreplaceable usability practice, since it gives direct input on how real users use the system...
on those designs. On the basis of such tests, the technology is (ideally) re-designed or (occasionally) the operational targets for user performance are revised. [Dillon, 2000].
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
Universal usability
Universal usability refers to the design of information and communications products and services that are usable for every citizen. The concept has been advocated by Professor Ben Shneiderman, a computer scientist at the University of Maryland, College Park...
, encompasses the standards and guidelines of design for accessibility
Accessibility
Accessibility is a general term used to describe the degree to which a product, device, service, or environment is available to as many people as possible. Accessibility can be viewed as the "ability to access" and benefit from some system or entity...
. Some primary 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 testingUsability testingUsability testing is a technique used in user-centered interaction design to evaluate a product by testing it on users. This can be seen as an irreplaceable usability practice, since it gives direct input on how real users use the system...
(Gold standard of Usability Engineering, but the most involved and expensive method) - interviews
- focus groups
- questionnaires/surveys
- cognitive walkthroughCognitive walkthroughThe cognitive walkthrough method is a usability inspection method used to identify usability issues in a piece of software or web site, focusing on how easy it is for new users to accomplish tasks with the system...
s - heuristic evaluationHeuristic evaluationA heuristic evaluation is a discount usability inspection method for computer software that helps to identify usability problems in the user interface design. It specifically involves evaluators examining the interface and judging its compliance with recognized usability principles...
s - RITE methodRITE MethodRITE Method, for Rapid Iterative Testing and Evaluation, typically referred to as "RITE" testing, is an iterative usability method. It was defined by Michael Medlock, Dennis Wixon, Bill Fulton, Mark Terrano and Ramon Romero. It has been publicly championed by Dennis Wixon while working in the...
- cognitive task analysisTask analysisTask analysis is the analysis of how a task is accomplished, including a detailed description of both manual and mental activities, task and element durations, task frequency, task allocation, task complexity, environmental conditions, necessary clothing and equipment, and any other unique factors...
- contextual inquiryContextual inquiryContextual inquiry is a user-centered design ethnographic research method, part of the Contextual Design methodology. A contextual inquiry interview is usually structured as an approximately two-hour, one-on-one interaction in which the researcher watches the user do their normal activities and...
- Think aloud protocolThink aloud protocolThink-aloud protocol is a method used to gather data in usability testing in product design and development, in psychology and a range of social sciences...
Usability testing
Usability testing
Usability testing is a technique used in user-centered interaction design to evaluate a product by testing it on users. This can be seen as an irreplaceable usability practice, since it gives direct input on how real users use the system...
, the gold standard, 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.
There are a variety of online resources that make the job of the Usability Engineer a little easier. Some examples of these include:
1. The Web Metrics Tool Suite 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:
- Web Static Analyzer Tool (WebSAT) - checks web page HTML against typical usability guidelines
- Web Category Analysis Tool (WebCAT) - lets the usability engineer construct and conduct a web category analysis
- Web Variable Instrumenter Program (WebVIP) - instruments a website to capture a log of user interaction
- Framework for Logging Usability Data (FLUD) - a file format and parser for representation of user interaction logs
- FLUDViz Tool - produces a 2D visualization of a single user session
- VisVIP Tool - produces a 3D visualization of user navigation paths through a website
- TreeDec - adds navigation aids to the pages of a website
2. The Usability Testing Environment (UTE) 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."
3. The UsableNet Liftmachine 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.
Research resources
Some well-known practitioners in the field are Donald NormanDonald Norman
Donald Arthur Norman is an academic in the field of cognitive science, design and usability engineering and a co-founder and consultant with the Nielsen Norman Group. He is the author of the book The Design of Everyday Things....
, Jakob Nielsen
Jakob Nielsen (usability consultant)
Jakob Nielsen is a leading web usability consultant. He holds a Ph.D. in human–computer interaction from the Technical University of Denmark in Copenhagen.-Early life and background:...
, and John M. Carroll
John M. Carroll (information scientist)
John M. Carroll is currently Edward M. Frymoyer Professor of Information Sciences and Technology at Penn State. Carroll is perhaps best known for his theory of Minimalism in computer instruction, training, and technical communication...
. Nielsen and Carroll have both written books on the subject of usability engineering. Nielsen's book is aptly titled Usability Engineering, and was published in 1993. Carroll wrote "Making Use: Scenario-Based Design of Human-Computer Interactions" in 2000, and co-authored "Usability Engineering: Scenario-Based Development of Human-Computer Interaction" with Mary Beth Rossen in 2001. Some other field leaders are Alan Cooper, Larry Constantine
Larry Constantine
Larry LeRoy Constantine is an American software engineer and professor in the Mathematics and Engineering Department at the University of Madeira Portugal, who is considered one of the pioneers of computing...
and Steve Krug the author of "Don't Make Me Think! A Common Sense Approach to Web Usability".
There are many books written on Usability Engineering. A few of the more popular recently published books are as follows:
1. 1993 - Usability engineering by Jakob Nielsen - 362 pages
2. 1999 - Web site usability: a designer's guide by Jared M. Spool, Tara Scanlon - 157 pages
3. 1999 - The Usability Engineering Lifecyle: A Practitioner's Handbook by Deborah J. Mayhew - 542 pages
4. 2000 - Usability Engineering by Xristine Faulkner - 244 pages
5. 2001 - Usability Evaluation and Interface Design: Cognitive Engineering ... by Michael James Smith, Richard John Koubek, Gavriel Salvendy, Don Harris - 1592 pages
6. 2002 - Usability engineering: scenario-based development of human-computer interaction by Mary Beth Rosson, John Millar Carroll - 422
7. 2003 - The human-computer interaction handbook: fundamentals, evolving technologies ... by Julie A. Jacko, Andrew Sears - 1277 pages
8. 2007 - Usability Engineering: Process, Products, and Examples by Laura M. Leventhal, Julie Barnes - 314 pages
9. 2008 - Adoption-centric Usability Engineering: Systematic Deployment, Assessment ... by Ahmed Seffah, Eduard Metzker - Computers - 450 pages
10. 2008 - The Human-Computer Interaction Handbook: Fundamentals, Evolving Technologies ... by Andrew Sears, Julie A. Jacko - 1358 pages
11. 2011 - Usability Engineering and E-Health In (Editors Martina Ziefle, Carsten Rocker) Human-Centred Design of E-Health Technologies, IGI Global, pp. 46-64, ISBN 1-60960-177-7 .
See also
- User interface engineeringUser interface designUser interface design or user interface engineering is the design of computers, appliances, machines, mobile communication devices, software applications, and websites with the focus on the user's experience and interaction...
- UsabilityUsabilityUsability is the ease of use and learnability of a human-made object. The object of use can be a software application, website, book, tool, machine, process, or anything a human interacts with. A usability study may be conducted as a primary job function by a usability analyst or as a secondary job...
- User experience designUser experience designUser experience design is a subset of the field of experience design that pertains to the creation of the architecture and interaction models that affect user experience of a device or system...
- Usability testingUsability testingUsability testing is a technique used in user-centered interaction design to evaluate a product by testing it on users. This can be seen as an irreplaceable usability practice, since it gives direct input on how real users use the system...
- World Usability DayWorld Usability DayWorld Usability Day or Make Things Easier Day promotes the value of usability, usability engineering, user-centered design, universal usability, and every user's responsibility to ask for things that work better...
- Component-Based Usability TestingComponent-Based Usability TestingComponent-based usability testing is a testing approach which aims at empirically testing the usability of an interaction component. The latter is defined as an elementary unit of an interactive system, on which behaviour-based evaluation is possible...