Upload
dirkswart
View
1.745
Download
0
Tags:
Embed Size (px)
DESCRIPTION
An introduction to usability for general audiences. It presents principles, three base rules and specific examples.
Citation preview
An Introduction to Usability
Dirk SwartWeb Technologies DirectorUniversity Communications
Keywords
Simplicity
User orientation
Trade-offs
Ease of use
Patterns
Reversability
Details
Why do usability?
Diebold Voting System Has 'Delete' Button for Erasing Audit Logs
Wired News (03/03/09) Zetter, Kim
Auditors report:
"The proximity of the clear button to the "print" and "save as" buttons raises the risk of the logs being erased accidentally, and the system provides no warning to operators of the danger of clicking on the button."
“Commandeer. Technical term. We’re going to commandeer that ship”.
Progressive disclosure: Showing overviews and hiding details until the user requests them.
Affective: Appealing to the emotions of the user.
Affordance: Property of a thing which determines how it is (or can be) used.
Insert photo of Mann Library doors
Academics for $200 please Alex
What do economists study most?
What do economists study most?
A: MoneyB: PeopleC: UtilityD: !@#$# economists!
C: Utility
We will call this ‘happiness’ or ‘satisfaction’.
“…changes in utility are sometimes
expressed in units called utils.” (Wikipedia)
For our purposes …
Something is Pareto Optimal if we can’t make someone better off without making someone else worse off.
Usability:
“The degree to which an object, device, software application, etc. is easy to use with no specific training”
- Wikipedia
Usability:
“The degree to which an object, device, software application, etc. is easy to use with no specific training”
- Wikipedia
“Quite simply, usability is making your site easy for your customers to find the exact information they need when they need it.”
– www.searchenginewriting.com
Usability:
“The degree to which an object, device, software application, etc. is easy to use with no specific training”
- Wikipedia
“Quite simply, usability is making your site easy for your customers to find the exact information they need when they need it.”
– www.searchenginewriting.com
“Usability is the study of how to Pareto optimize your website or application”
User Experience: “Impression left in a person's mind after the sum of a series on interactions.”
Q: Who decides if a website is easy to use?
A: Your target audience
But that is not very informative - will discuss more.
Click … Whirr
Fixed Action Pattern:A behavioral sequence that runs to completion.
It has a trigger feature (releaser) plus a sequence, and in people is usually cultural.
Our take home: People like patterns.
We’ll come back to this in a bit.
Q:
Form Follows Function
Beyond the introductory level this principle becomes morecomplicated. But this is an introduction to usability, so we’ll stick with it
We’ll come back to this in a bit too.
Function first. Then form.
Rule 1
Rule 1
Web behavior is always rushed:
Your website is a means to an end.
Implications
Good design ≠ easy to use.
Simplicity is a choice.
Total Visitor time =
search time + load time + browse time+ scan time
Think utility.
Consistency & Expectations
Rule 2
Patterns Count
Thinky things …
Interlude
Ready to hand
Present at hand
OK, back to work
People
expect
patterns
Rule 2
Looks right, but isn’t
Law School vanishing menus
People try stuff
Rule 3
Implications
Words Count. Words are the steak, not the sizzle.
(And use sans serif, scalable. No A-A band aid crap)
Implications
Plan for the scent of information.
Be reversible. Allow users to undo mistakes.
Garden Path: a sequence of actions a user takes that each seem to be leading to the desired outcome but don't produce the desired result in the end.
Don't let the exciting, the periphery, drive you out of your core business
Rule 3
Don’t focus on everything equally: Vegas effect.
What is the most important: remember economics
Rule 4
It’s ALL details
Bonus
Common Mistakes
Heavy Pages <- violates rule 1
When OK? If you have a pattern. Eg: Amazon.com
Heavy Pages <- violates rule 1
When OK? If you have a pattern. Eg: Amazon.com
Ambiguous choices <- violates rule 3
Ambiguous choices <- violates rule 3
Lack of focus - Violates rule 4?
Summary• Usability is important. You think so
they don’t have to.
• Every decision is a trade-off.
• If you can, separate design, usability, focus, user experience. They are different.
• Learn the vocabulary
More Information? • MIT Usability Guidelines:http://web.mit.edu/is/usability/usability-guidelines.html
• SUS, a quick and dirty usability scalehttp://www.usabilitynet.org/trump/documents/Suschapt.doc
• Designing for the Scent of InformationEmail me for a copy
• Vocabularyhttp://www.usabilityfirst.com/glossary/main.cgi
• Humorhttp://www.ok-cancel.com
• Yahoo Design Pattern Library http://developer.yahoo.com/ypatterns/
"Civilization advances by extending the number of operations we can perform without thinking about them“
Alfred North Whitehead
(1861 – 1947)
Usability Testing• End User Usability
– 161 Secondary School Teachers filled in on line form.
• 73% had no affiliation to Cornell, 7.5% were Cornell alums.
• 46% were not within driving distance of Cornell.
• Admin Usability– 8 Detailed interviews (1 hr +) conducted
on 1 day.
• Effort to produce these results:– End user: 160 hours over a month,
Admin; 45 hours over three weeks.
Usability Findings - Overall• 68.3% used the net to find
educational information– 37% had never looked for educational
materials at Cornell. 27% had looked “once or twice”
– They expected access to a very broad range of material.
– 33% would expect to find material in ‘Outreach’ section.
Usability Findings - Interface• Search
– 55% of respondents did not like the “simple search”.
– Simple search with Primary and Secondary browse was most preferred.
• Browsing as a hierarchical sequence “is desirable” > 86%)
– >90% said program profile page was well designed.
• Search + Browse ‘front and center’ is essential.
Key Features of our execution• Search and Browse
• Not trying to replace other sites. Refers people onward at Cornell.
• Reports: – Ability to revise search and browse. – Add to taxonomy– Track and count search terms
Example: Alice and Bob
Usability
Economics Psychology Human Factors Tips &Tricks4 Rules
BauhausClick, Whirr
Choices, choices
ScentUtility Theory SUSExamples
More information