Usability: Core Concepts
What defines usability?
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Learnability: Is the system easy to learn so users can start working right away?
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Efficiency: Is it efficient to use; can work be completed productively?
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Memorability: Is it easy to remember how to use the system?
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Errors: System should have low error rate, and users should be able to easily recover from them.
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Satisfaction: Is the system pleasant to use? Do users like using the product; and is the experience satisfying?
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Ten Usability Heuristics of Jakob Nielsen
These are ten general principles for user interface design. They are called “heuristics” because they are more in the nature of rules of thumb than specific usability guidelines
Visibility of system status
The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.
Match between system and the real world
The system should speak the users’ language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.
User control and freedom
Users often choose system functions by mistake and will need a clearly marked “emergency exit” to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.
Consistency and standards
Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.
Error prevention
Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.
Recognition rather than recall
Minimize the user’s memory load by making objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.
Flexibility and efficiency of use
Accelerators €”unseen by the novice user €”may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.
Aesthetic and minimalist design
Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.
Help users recognize, diagnose, and recover from errors
Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.
Help and documentation
Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to search, focused on the user’s task, list concrete steps to be carried out, and not be too large.
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References:
Barnum, C. (2002). Usability testing and research. Longman: New York.
Neilsen, J. (2003) Usability 101: Introduction to usability. Retrieved August 30, 2007, from http://www.useit.com/alertbox/20030825.html
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Usability: Resources
Research-based Web Design and Usability Guidelines: from the U.S. Department of Health & Human Services.Current research-based guidelines that will help you withusable Web design. The PDF document is 100 MB and free for you to download and utilize.
Usability.gov. Very straight forward advice and research on usability for Website design and development. Useful and poignant.
Usability Glossary. Confused about usability terminology. What is SME?
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Usability: MIT Usability Resources
MIT provides unique opportunities to learn from some of the brightest minds in the world. This is quite significant as MIT offers courses and streaming video at no cost. Their efforts are supported by generous individuals and institutions around the world.
“MIT World „¢ is a free and open site that provides on-demand video of significant public events at MIT.”
If one is interested in learning about usability from MIT, it is permissible to download lecture notes from the school as part of their open learning policy.
MIT: User Interface & Design Course
User Interface Design and Implementation
Massachusetts Institute of Technology
Department of Electrical Engineering and Computer Science
Fall Semester, 2006
MIT: Emerging Technologies Conference
MIT: Recommended booklist for usability
Norman, D. A. The Design of Everyday Things. New York, NY: Doubleday, 1990. ISBN: 0385267746.
This little book is a classic work on usability, not just of computer interfaces but also of physical objects like doors, showers, and stoves. Full of great anecdotes, plus theory about how users form models in their heads and how users make errors. Belongs on every engineer’s shelf.
Nielsen, J. Usability Engineering. Burlington, MA: Academic Press, 1994. ISBN: 0125184069. Somewhat dated but still useful handbook for discount usability engineering, covering many of the evaluation techniques we’ll be learning in this class.
Mullet, K., and D. Sano. Designing Visual Interfaces: Communication oriented techniques. Upper Saddle River, NJ: Prentice Hall, 1994. ISBN: 0133033899.
A terrific guide to graphic design, chock full of examples, essential principles, and practical guidelines. Many programmers have a fear of graphic design. This book won’t teach you everything — it still pays to hire a designer! — but it helps get over that fear and do a competent job of it yourself.
Baecker, R. M., et al. Readings in Human-Computer Interaction: Toward the Year 2000. San Francisco, CA: Morgan Kaufmann, 1995. ISBN: 1558602461.
Shneiderman, B. Designing the User Interface: Strategies for Effective Human-Computer Interaction. 4th ed. Reading, MA: Addison-Wesley, 2004. ISBN: 0321197860.
Dix, A., et al. Human-Computer Interaction. 2nd ed. Upper Saddle River, NJ: Prentice-Hall, 1998. ISBN: 0132398648.
Olsen, D. R. Developing User Interfaces. San Francisco, CA: Morgan Kaufmann, 1998. ISBN: 1558604189.
Tufte, E. R. The Visual Display of Quantitative Information. Cheshire, CT: Graphics Press, 1983. ISBN: 0318029928.
Raskin, J. The Humane Interface: New Directions for Designing Interactive Systems. New York, NY: ACM Press, 2000. ISBN: 0201379376.
Johnson, J. GUI Bloopers: Don’ts and Do’s for Software Developers and Web Designers. San Francisco, CA: Morgan Kaufman, 2000. ISBN: 1558605827.
Card, S. K., T. Moran, and A. Newell. The Psychology of Human-Computer Interaction. Hillsdale, NJ: Lawrence Erlbaum, 1983. ISBN: 0898598591.
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Usability Reference Books
1. Don’t Make Me Think: A Common Sense Approach to Web Usability
Amazon.com
Usability design is one of the most important–yet often least attractive–tasks for a Web developer. In Don’t Make Me Think, author Steve Krug lightens up the subject with good humor and excellent, to-the-point examples.
The title of the book is its chief personal design premise. All of the tips, techniques, and examples presented revolve around users being able to surf merrily through a well-designed site with minimal cognitive strain. Readers will quickly come to agree with many of the book’s assumptions, such as “We don’t read pages–we scan them” and “We don’t figure out how things work–we muddle through.” Coming to grips with such hard facts sets the stage for Web design that then produces topnotch sites.
Using an attractive mix of full-color screen shots, cute cartoons and diagrams, and informative sidebars, the book keeps your attention and drives home some crucial points. Much of the content is devoted to proper use of conventions and content layout, and the “before and after” examples are superb. Topics such as the wise use of rollovers and usability testing are covered using a consistently practical approach.
This is the type of book you can blow through in a couple of evenings. But despite its conciseness, it will give you an expert’s ability to judge Web design. You’ll never form a first impression of a site in the same way again. –Stephen W. Plain
Topics covered:
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User patterns
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Designing for scanning
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Wise use of copy
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Navigation design
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Home page layout
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Usability testing
Book Description
People won’t use your web site if they can’t find their way around it. Whether you call it usability, ease-of-use, or just good design, companies staking their fortunes and their futures on their Web sites are starting to recognize that it’s a bottom-line issue. In Don’t Make Me Think, usability expert Steve Krug distills his years of experience and observation into clear, practical–and often amusing–common sense advice for the people in the trenches (the designers, programmers, writers, editors, and Webmasters), the people who tell them what to do (project managers, business planners, and marketing people), and even the people who sign the checks.
Krug’s clearly explained, easily absorbed principles will help you sleep better at night knowing that all the hard work going into your site is producing something that people will actually want to use.
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Make a difference in usability!
It’s not everyday or everyone that can say they help with usability testing for Microsoft. According to their Website, their research group seeks usability testers in order to help with product development:
Get involved in the product development process and help us understand your needs by signing up to participate in one of our Usability Research studies. Whether this is your first time using a computer, or the computer is a daily part of your life; we have studies for everyone to participate in.
Where do we do the research?
While most of this research revolves around Lab Studies or Focus Groups conducted on our main campus in Redmond, WA (U.S.A.), we also conduct on-line surveys and Field Studies for individuals who reside outside of this region.
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Usability Reference Books
Microsoft Usability Biography: A listing of very good resources.
Gergle, D. Brinck, T. & Wood, S.(2002). Usability for the Web: Designing Web sites that work. New York: Morgan Kaufmann
Barnum, C. (2002). Usability testing and research. New York: Longman.
Preece, Rogers, & Sharp. (2002). Interaction design. New York: Wiley & Sons.
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Usability Articles of Interest:
Smashing Magazine: 30 Usability Issues to be aware of
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Usability Websites of Interest:
Jakob Nielsen: One of the foremost experts in usability.(Ironically his Website is rather hard to read. However go with an open mind and you will benefit from his solid research and professional opinion.) Also he produces an email alert that can you can subscribe to for free which has much valuable information.
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Usability Testing Software
At some point you will want to test usability for a Website project. But alas, your testing group may bescattered around the world. The followingsoftware may be of help.
UserVue is an online service that lets you remotely observe and record users’ desktops as they navigate applications and sites. It’s made by the same people who made Camtasia and Snag it, which are tools I use every day.
- Perform user testing
- Conduct user research
- Collect design feedback
- Collaborate on projects
- > See a demo videoof how it works.