Usability* = GOOD

*a/k/a ‘ease of use’

You see it everywhere…Consumer Reports:

CNET…

Yahoo…

But what is usability, really?

• “A quality attribute that assesses how easy user interfaces are to use”

• Refers to methods for improving ease-of use during the construction phase—for instance, usability testing

Why do usability testing?

• The point of testing is not to prove or disprove something. It's to inform your judgment. People like to think, for instance, that they can use testing to prove whether navigation system "a" is better than navigation system "b," but you can't. No one has the resources to set up the kind of controlled experiment you'd need. What testing can do is provide you with invaluable input which, taken together with your experience, professional judgment, and common sense, will make it easier for you to choose wisely—and with greater confidence—between “a” and “b.”

• --Steve Krug, Don’t Make Me Think

IF SOMETHING IS HARD TOUSE, I JUST DON'T USE IT ASMUCH.

-- Melanie Krug

The 5 quality components

of usability:• Learnability: How easy is it for users to accomplish basic

tasks the first time they encounter the design? • Efficiency: Once users have learned the design, how

quickly can they perform the tasks?

• Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?

• Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?

• Satisfaction: How pleasant is it to use the design?

The 5 quality components of usability, cont.--

• Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?

• Efficiency: Once users have learned the design, how

quickly can they perform the tasks?

• Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?

• Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?

• Satisfaction: How pleasant is it to use the design?

•Visibility of system status •Match between system and the real world •Consistency and standards•Aesthetic and minimalist design

•Visibility of system status •Match between system and the real world •Consistency and standards•Aesthetic and minimalist design

•User control and freedom •Flexibility and efficiency of use

•User control and freedom •Flexibility and efficiency of use

Recognition rather than recall

Recognition rather than recall

•Error prevention•Help users recognize, diagnose, and recover from errors•Help and documentation

•Error prevention•Help users recognize, diagnose, and recover from errors•Help and documentation

Aesthetic and minimalist design

Aesthetic and minimalist design

Aesthetic and minimalist design

Aesthetic and minimalist design

What makes usability so important?

• Users are consumers—they don’t have to use your site/app

• Users don’t read pages—they scan them

• Users don’t choose the best option—they choose the first reasonable option

…& one grim little table:

User tasks Success rate*

1. Shopping on ecommerce sites

56%

2. Subscribing to email newsletters

78%

3. Other tasks 63-73%

4. Using Web-based applications

45%

Avg. success rate 65%

* users’ ability to accomplish their tasks

Usability Myths

1. Too costly or not quantifiable

2. Bites into the schedule3. Stifles creativity

Myth #1: Too costly or not quantifiable

• Not pricey: the grand usability labs of years gone by =»

• Get users from behind your own firewall• Lab, schmab: use a conference room and a

notepad (& maybe someone’s camcorder?)• “Lost-our-lease testing”: < $300

• Heck, yeah, it’s measurable!

Myth #2: It’ll delay the launch date

• Basic user testing can be finished in 2-3 days

• Paper prototyping• You don't have to spend time coding

features users don't need• Settles design disputes in the Dev

team

• Design standards are like a dictionary…

• A standard ensures that users can understand the individual interface elements in the design

• Consistency is one of the strongest contributors to usability

Myth #3: It stifles designers’ creativity

Design guidelines = GOOD

Usability Rock Stars

• Jakob Nielsen• Don Norman• Bruce Tognazzini• Steve Krug

Usability ResourcesBooks

• Nielsen, Jakob. Designing Web Usability: The Practice of Simplicity. New Riders, 2000.

• Nielsen, Jakob, and Tahir, Marie. Homepage Usability: 50 Websites Deconstructed. New Riders, 2002.

• Rubin, Jeffrey. Handbook of Usability Testing: How to Plan, Design, and Conduct Effective Tests. John Wiley & Sons, Inc., 1994.

• Tufte Edward R., Visual Explanations. Graphics Press, 1997.• Norman, Donald A. The Design of Everyday Things. Basic

Books, 1988.• Krug, Steve. Don't Make Me Think: A Common Sense

Approach to Web Usability. New Riders, 2006.• Bias, Randolph, and Mayhew, Deborah. Cost-Justifying

Usability : An Update for the Internet Age. Morgan Kaufmann, 2005.

Even more resources…

Usability Websites

www.useit.com (Nielsen's site) www.sensible.com (Krug's website) www.jnd.org (Don Norman's site) www.asktog.com (Tognazzini's site) www.formsthatwork.com (Caroline Jarrett's site) www.webword.com & www.usabilityviews.com (blogs) http://usability.gov/guidelines/index.html (research-

based guidelines) www.uie.com (Jared Spool's website)