dimensions of usability · 10 dimensions of usability | whitney quesenbery | upa 2003 19 creating a...

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Dimensions of Usability:Starting the ConversationDriving the Process

Whitney QuesenberyWhitney Interactive Design, LLC

[email protected]

©2003 Whitney Quesenbery

DIMENSIONS OF USABILITY | WHITNEY QUESENBERY | UPA 2003 2

Defining the problem

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#1 - What do we mean by “usability”?

A result: designthat works forpeople

Techniques for learningabout and from users

PROFILEMary,Clerk

A user-centered design process

ENVISION DISCOVERY DESIGNFOUNDATION

DESIGNDETAILS BUILD RELEASE

A philosophy forapproaching design


#2 - Clear communications

How manydifferentthings are

they talkingabout?

■ ease of use■ user friendly■ efficiency■ effective■ satisfying■ memorable■ pleasure■ accessible■ learnability■ findability■ quality■ usefulness■ error-averse

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“The extent to whicha product can beused by specifiedusers to achievespecified goals witheffectiveness,efficiency andsatisfaction in aspecified context ofuse” - ISO 9241-11

"A usable product or process is onethat is learnable, efficient,memorable, error-averse, andsatisfying." - Dick Miller

" Usability means providing valuethat users can see themselves.”

- Ginny Redish

• learnability• efficiency• memorability• errors (low rate, easy to recover)• satisfaction

- Nielsen,Usability Engineering

#3 - An “actionable” definition


■ How do we articulate the issues with…

■ Colleagues■ Clients■ Managers■ Friends■ Developers■ Business

stakeholders

...and all our other collaborators?

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Dimensions of usability


The 5 Es

■ EffectiveThe completeness and accuracy withwhich users achieve their goals.

■ EfficientThe speed (with accuracy) in which userscomplete their tasks

■ EngagingHow pleasant, satisfying or interesting aninterface is to use

■ Error tolerantThe ability of the interface to preventerrors or help users recover from thosethat occur

■ Easy to learnHow well the product supports both initialorientation and deeper learning

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Effective

Questions to ask■ How do users define

success?■ How does the business

define success?■ What are the goals;

what are the tasks?■ Are there hidden goals?

The completenessand accuracy withwhich usersachieve theirgoals.


Efficient

Questions to ask■ How long do users

expect that task to taketo complete?

■ Can the goals bereached in a singlesession?

■ What styles ofinteraction do usersprefer, or are possible?

■ What would make theinterface feel efficient.

The speed (withaccuracy) in whichusers completetheir tasks

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Engaging

Questions to ask■ What kind of work (or play)

does the product support?■ What are the expectations

for style and tone?■ How long/short is a typical

interaction?■ How frequently is the

product used?■ What is the motivation to

use the product?■ What is the context of use?

How pleasant,satisfying orinteresting aninterface is to use.


Error TolerantQuestions to ask

■ What kinds of errors are likelyto occur?

■ How serious is theconsequence of an error?

■ Does the design help preventerrors?

■ How much support or guidanceare users likely to need tounderstand choices they haveto make?

■ What is the terminology thatthe users will know; what willbe unfamiliar or difficult?

The ability of theinterface toprevent errors orhelp users recoverfrom those thatoccur.

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Easy to Learn

Questions to ask■ How familiar will users

be with the product oninitial use?

■ What are theirexpectations for trainingor other guidance?

■ How many differenttasks or uses does theproduct have?

■ How often will theproduct be used?

How well theproduct supportsboth initialorientation anddeeper learning.


A question of balance

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A question of balance

For repetitive tasks, the mostimportant dimensions might beEfficient and Error Tolerant, sousers can work quickly withoutmistakes

Effective

Engaging

Easy to Learn

Error Tolerant

Efficient

Efficient

Error Tolerant

Effective

Engaging

Easy to Learn

For an infrequent task, the mostimportant dimensions might beEasy to Learn and Engaging,because users need to beguided through the task.


Starting the conversation

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Let’s try it...

■ For one of your currentprojects…

What would the users sayabout each of the 5Es?

■ Make the statements in thefirst person

■ Be concrete and specific


What makes this easy…or hard?

■ How much you know about the users, scenarios,personas and context of use

■ How many different user groups there are

■ How balanced a perspective you have had on thedesign problem

■ How practiced you are

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Creating a starting point

■ Find out how the team defines usability….

■ Collect their personal opinions about usability

■ Introduce and define the dimensions of usability

■ Explore each in relationship to business goals

■ Examine the broad requirements for implications

■ Discuss possible usability priorities for the product

Be concrete, elicit specific examples for comparison


What do (they think) users think?

■ Repeat from the users point of view….

■ Collect examples of things a user might say, andrelate it to one of the 5Es

■ Discuss how many different user groups theremight be, and differences between them

■ Capture what these examples are based on, andgaps this might reveal in the group’s knowledge

The goal is to uncover tacit and explicit assumptions

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What do users really think?

■ Prepare to repeat from actual evidence….■ Does actual experience with users match the

assumptions in the previous exercise?■ Are there differences in perceptions in different

stakeholder groups?■ Where are the gaps in understanding, and how

can they be filled?

Where do you have knowledge; where do you need knowledge


Find the balance of priorities

■ Determine relative importance ofeach dimension

■ Rank them in priority order■ Repeat for each user group or

persona (and possibly forbusiness goals)

The goal is to find points of tension that must be resolved in the design

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Make it a game

■ Give the group $100 in play money

■ Ask them to spend on it on the 5Es

■ They have to spend all of the money

■ They have to buy all of them

■ But, some Es will be more valuable than others

So… let’s try it.


A museum web site

effective

efficient

engaging Is this museum interesting? What does it haveto offer?

I need answers to simple questions. The website should be up to date and accurate.

Will it be faster to phone them up?

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An online exhibition

effective

easy to learn

engaging Who is Weegee and why should I beinterested in him?

Where is this exhibit, and how can I see it?

I just want to look around and see what thissite offers.


A registration update form

efficient

error tolerant

easy to learn

This won’t mess me up will it? I don’t want anyproblems using the service.

What do all these things mean? I don’t alwaysunderstand what they are asking me?

If this takes too long, I’ll just try somewhere else.

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An intranet document library

effective

efficient

easy to learn

I just want to find the document I need.

I took library class in high school. Don’t tell me Ihave to learn how to use this.

Is this everything? There’s so much out there thatyou never know.


Starting the conversation

■ The 5Es are a starting point…

■ The best positive outcome is a shared understanding youcan use to move the project forward

■ Be prepared to be flexible■ Let the team make adjustments if they need to

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Driving the process


User research and the 5Es

■ Map user quotes to the 5Es■ Their concerns and issues set the balance and priorities

efficient

effective

engaging

“I really hope that I’ve gotten the privacysettings right so I don’t get email”

“At least the text is big enough to read”

“This looks like a lot to read. How long will thistake, anyway?”

error tolerant “Can I make a change as often as I like? What if Iget it wrong?”

easy to learn “I never understand the questions they are askingme in these forms!”

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Using the 5Es suggest design approaches

effective • eliminate opportunities for error• provide feedback on all actions

accuracy

efficient • provide just information needed• navigation for workflow and alternate paths• appropriate interaction styles

operationalspeed

engaging • make interface helpful with minimal prompts and instructions

draw users in

error tolerant • transform ‘errors’ into corrections• use controls that aid in selection

validation

easy to learn • create guided interactions or process funnels”

just in timeinstruction

Dimension User Needs Design Approaches


Matching 5Es to testing techniquesDimension Types of usability testing needed

evaluate tasks for how accurately they werecompleted and how often they produce errors

effective

error-tolerant

easy to learn control how much instruction is given to testparticipants, or recruit participants with differentlevels of knowledge

construct task scenarios to create situationswith potential problems

engaging user satisfaction surveys to gauge acceptancereview logs for ‘time on site’

efficient time tasks with realistic tasks and workingversions of the software

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More reading

"Dimensions of Usability" inContent and Complexity:Information Design in TechnicalCommunication, eds. MichaelAlbers, Beth Mazur.Erlbaum, 2003 ISBN: 0805841407

And, additional articles on my web site:

http://www.WQusability.com


Contact Information

Whitney QuesenberyWhitney Interactive Designp: 908-638-5467e: [email protected]: www.WQusability.com

Whitney Quesenbery designs interfaces for projects from web sites toapplications and helps companies implement a user experience capability toimprove the usability of their products. She is an expert in developing newconcepts that achieve the goal of meeting business, user and technologyneeds.

As a developer of LUCID (Logical User-Centered Interaction Design), shepromotes the importance of a user-centered approach and usability in design.

Whitney is a director of the Usability Professionals’ Association(www.upassoc.org), and web site manager for the STC Usability SIG(www.stcsig.org/usability/)

© 2003, Whitney Quesenbery - Whitney Interactive Design

Dimensions of Usability: Defining the Conversation, Driving the Process

EffectiveThe completeness and accuracy with which usersachieve their goals.

How do people define success?

EfficientThe speed (with accuracy) with which this work can bedone.

What makes a task feel “too long?”

EngagingHow pleasant, satisfying or interesting an interface is touse.

Does it draw people into the interaction?

Error TolerantHow well the product prevents errors, and helps the userrecover from any that do occur.

Is the interface helpful or does it create dead endsand punitive rework?

The 5Es of Usability

The 5Es balance usability requirements,showing relative importance

Easy to LearnHow well the product supports both initial orientation anddeeper learning.

Is it easy to remember, explore and innovate with thisproduct?

What would the people who use your product say?

Effective I…

Efficient

Engaging

Error Tolerant

Easy to Learn

dimensions of usability · 10 dimensions of usability | whitney quesenbery | upa 2003 19 creating a...

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