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