Usability with Project Lecture 8 – 3/10/08

© Simeon Keates 2008

Usability with ProjectLecture 8 – 3/10/08Dr. Simeon Keates


Exercise – part 1

Last week you were asked to prepare a plan for testing the accessibility of your own site

This week…

…do it!


Exercise – part 2

Prepare a 5 minute presentation Address the following questions:• Did you consider accessibility issues when you designed the site?• What was your testing plan?• Which user capabilities did you test for (e.g. colour blindness)?• What further tests do you think are necessary? • With the knowledge of accessibility issues that you have gained, would you

have designed the site differently if “accessibility” had been a stated design goal at the outset? If so, how?

Order of presentations:• Group 2, 4, 6, 1, 3, 5


Assessment of DTT STBs...


A systems overview

User

Remotecontrol

Service provider

Television

Remotecontrol

Set top box (STB)


Motivations for study

Commissioned by UK Department of Trade and Industry Wanted to find out who could not access DTT Original focus on ‘the disabled’ Definition broadened...

Why?


Typical assessment methods used in this research

Expert assessment

Exclusion analysis

User observation

Questionnaires

Interviews

Focus Groups

Assessment of STBs

Customer expectations


Methodology - Choice of STBs

2 STBs chosen for study STB1 - marketed as “easy to use” STB2 - market leader

1 digital satellite system chose as comparison STB3 – developed by content provider


Expert assessment

4 assessors 2 with DTV experience, 2 without STB protocol only Aims to identify most likely sources of problems• Define protocol for following assessments


Methodology - Analogue TV protocol

6 activities• Switch on• Change channel• Change volume• Teletext (find local weather)• Subtitles (on/off)• Switch off


Methodology - STB protocol

8 activities• Installation• Switch on• Change channels (direct + EPG)• Change volume• Teletext (find local weather)• Subtitles (on/off)• BBCi (find local weather)• Switch off


Expert Assessment - Results

13 major sources of difficulty found 4 – Installation and set-up• e.g. instruction manual, initial tuning

5 – Operation • e.g. multiple modes, subtitles

4 – Remote controls• e.g. labelling, layout


Exclusion analysis

Systematic analysis Combined with data from Office of National Statistics• Population data 1996/7 UK Disability Follow-Up Survey

Aims to calculate how many people have the difficulties highlighted by expert assessment• How many people in the user observation should have those difficulties?


Example – breakdown of installation

High-level activities Medium-level activities

Unpack STB cut through outer packaging, open box, pick up contents, put down contents, find and recognise instructions

Follow instructions open and hold instructions, read instructions, understand instructions

Plan cable connections (what goes where) match box contents to instructions, identify AV components (e.g. VCR, TV, amplifier, speakers) and cables, plan signal flow, identify cables to be moved

Move components to get access to cable slots grip components, pull forward

Disconnect cables to be moved identify cables, grip and pull them

Place STB near AV components pick up and carry STB, put it down

Connect cables in correct order identify cables, identify cable sockets, pick up cables, connect them

Replace AV components to usual position grip components, push back


Exclusion analysis - Results

25

20

15

10

5

0

Analogue DTV Analogue DTV

16+ 75+

Pop

ulat

ion

(,00

0s)


Exclusion analysis - Results

25

20

15

10

5

0

25

20

15

10

5

0

Analogue DTV Analogue DTV

16+ 75+

Pop

ulat

ion

(,00

0s)

Pop

ulation(%

age)


User observations - Overview

13 users - 12 aged 60+, 1 aged 24• 9 no DTV experience• 2 owned STBs• 1 owned satellite box• 1 owned iDTV• 7 PC users, 6 non-users

All ‘independent’ living


User observations - Methodology

2 hour sessions comprising: 30 minutes briefing 60-75 minutes with equipment• 15-20 minutes analogue• 40-60 minutes DTV• 2 STBs

15 minutes debriefing


User observations - Set-up


The users…


User observations - Example visual problems

Finding buttons on r/c • Especially POWER

Switching between r/c and screen• Different pairs of glasses

Reading on-screen font • No zoom facility

Reading instruction manual• Small print

New difficulty


User observations - Example motor problems

Pressing buttons on r/c

• Size and shape

Time-outs

• e.g. on EPG (040 -> 004)

Arrow button overshoot

• Oscillating cursor

New difficulty

New difficulty


STB2 remote control


STB1 remote control


User observations - Example ‘cognitive’ problems

Use of OK/SELECT Inconsistent language (OK=SELECT?) Which r/c to use / which mode am I in? How to start/navigate BBCi/Teletext? How to call up/navigate on-screen menus? How to operate/navigate the EPG? Inconsistent layout • e.g. LHS on screen, RHS on r/c


User observations - Summary of results


Summary

Cognitive/experience issues most important

Many of the problems easily avoidable


Origins of the problems for older users

New language / terminology • Jargon

New input paradigms• Part TV, part PC

New interaction concept• Interacting with STB, not TV

Inadequate explanationClassic case of

“designers designing for themselves”


Implications of prevalence of cognitive difficulties

What does this mean for assessment methods?• Single assessment methods vs. multiple?• In what order should they be used?

What does this mean for designers?• How to design for different experience?


Designing for cognitive support


Background

International Symposium• Held in October 2005• Venue: IBM TJ Watson Research Center• Sponsored by: IBM HA & AC• 10 invited experts

Data presented here from that Symposium


Defining C&LDs

US medical community definition• “A cognitive disability arises from an impairment that affects IQ”• i.e. effects capability to acquire, process and utilise knowledge• Arises from how medical conditions are diagnosed and treated

Educators focus on learning difficulties• Often focused on educational attainment

Do behavioural difficulties count?• Some say yes, some say no

No single, clear definition. Mostly focused on what users cannot do


Defining C&LDs for UI design

Alternative definition needed for UI design• Need to understand what users are capable of• Not what they cannot do

Need functional descriptions of capabilities Descriptions tailored to design project


Prevalence of C&LDs - US statistics

When asked • “Have you had a physical, mental or emotional condition lasting 6 months or

more that made it difficult to learn, remember or concentrate”

5.2% of all US adults agreed• (Source: 1999-2004 American Community Survey)


Prevalence of C&LDs - GB statistics

5.6% of GB adults self-report some form of cognitive impairment• (Source: 1996 Disability Follow-Up Survey)

“Cognitive impairment” comprised of:• Communication

• E.g. “Has some difficulty understanding what other people say or what they mean”

• Intellectual Functioning• E.g. “Often forgets what was supposed to be doing in the middle of something”

Figures from both surveys are most likely conservative


Role of cognition in interaction

Model Human Processor (Card, Moran and Newell)

F(t) = xp + yc + zm

where

• p = perceptual time unit

• c = cognitive time unit

• m = motor function time unit

• x, y, z are integers


Role of cognition (cont.) - Simplex II

“Cognition” comprises:• Working memory• Emotions and drives• Perception• Output• Feedback• Complex output sequences• Cognitive models• Long-term memory• Executive functions

(Adams)


Why C&LDs are not commonly addressed in UA…

They are often difficult to diagnose• Perception issues are easy to diagnose, cognitive ones are not

Many do not have a “universal” diagnosis• E.g. what exactly is dyslexia?

Many people with them are reluctant to admit this• The “invisible” impairment - stigma

Designing for them is not easy• No clear description of C&LD makes design more difficult

Can be assisted by “design best practices”


1 - Involve users in design process

“Standard” UA advice Can act as design partners• Working with designers

User study participants• Issues regarding ethical approval

The more designers know about their users,

the better their designs become


2 - Find required set of demands to complete the task

Every task has associated capability demands• Writing a letter, using an ATM, etc.

Every IT system has associated capability demands• Navigation, interaction, etc.

Designers should ensure that IT system demands

are no more than the task demands


3 - Use scaffolding techniques

New concepts need to be supported in multiple ways

New

concept

Existing

concept

New

concept

Existing

concept

Existing

concept

Existing

concept

The more references to existing knowledge,

the more stable the new knowledge


4 - Use positive reinforcement

Many people with C&LD have low self-esteem• Perceived stigma• Often branded as “failures” or “thick” as children• Are used to being “judged”

IT is attractive because it is not so quick to “label”• Designers need to build on this perception• Avoid negative comments• Provide positive support and reinforcement


5 - Design for user’s learning strengths

Not everyone has uniform C&LDs Need to design to user strengths, e.g. …

Older adults • often have poor “dynamic” memory• often have good “crystalline” memory

People with dyslexia• written instructions hard to follow• visual / auditory instructions easy to follow

Relate new concepts to familiar ones

Use multiple modalities


6 - Design for flexibility

E.g.: Offer sliding scales of complexity

Save Print

File Edit Format

File Edit View Insert Format Tools

Basic word processor

Mid-level word processor

High-level word processor

Allow users to proceed at their own pace


6 - Design for flexibility

E.g.: Offer sliding scales of complexity


7 - Chunk information

Difficult:• “The 2007 Jeep Grand Cherokee Overland has a 5.7L Hemi engine that

develops 330 BHP. It’s a willing a responsive engine. Prices for this model start at around $37,000 and go up to $44,000 for a fully specced up version.”

Better:• Model: Jeep Grand Cherokee Overland• Engine: 5.7L Hemi• Price: $37,000 - $44,000

Small bits of knowledge at a time


8 - Keep hierarchy depths to a minimum

As a general rule, depths should be <3

is better than:

Breadth, not depth

Potential conflict with motor/sensory issues


9 - Recognise the use of coping strategies

Try to complement, support or augment these


Other best practices - I

Use clear language• Avoid jargon

Provide appropriate “help” functionality• Concrete, repeatable, focused and consistent

Present assistance options carefully• Make sure to avoid “stigma”


Other best practices - II

Avoid “feature creep”• Difficult for older users who rely on crystalline memory

Try to be consistent• Consistent methods of exiting, for example


Summary

Cognitive and learning difficulties are the “invisible” impairment They are widespread (c. 5% of the population) They affect how well users can interact with UIs But receive comparatively little research and design attention

Need more attention!


For further details

ACM SIGACCESS Newsletter:• September 2005 Number 83• http://www.acm.org/sigaccess/newsletter/sept05.php

International Journal on UA in the Information Society• Volume 5, Number 4, April, 2007


Exercise


Exercise

Last week you were asked to prepare a plan for testing the accessibility of your own site

This week…

…do it!

Today – make the coding changes and test your sites again

Also remember to make the changes from your heuristic evaluations


Back to normal on Wednesday!

Back in 2A14

Also, please bring in at least one of each of the following:• Mobile telephone• “Landline” telephone• Television remote control• + one more product of your choice…

Usability with Project Lecture 8 – 3/10/08

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Transcript of Usability with Project Lecture 8 – 3/10/08