usability and accessibility lecture 5 – 02/03/10

© Simeon Keates 2010

Usability and AccessibilityLecture 5 – 02/03/10


Heuristics as a design approach


Setting the scene

“Rehabilitation Robotics in Europe” c.1997 EU funded many projects under TIDE initiative LOTS of money!!!

Projects generally major disasters Let’s see why…


An example – The EPI-RAID robot


EPI-RAID failed because…

No in-built market to sell to• Had to sell on its own merits

Too expensive • (~5000000DKK)

Overtaken by new technology• Internet

Not enough consideration of what it was to be used for• Too much focus on the technology

Needed a user-centred design approach!


Question

Can we use Nielsen’s heuristic in the design process?

i.e. not just for post-hoc testing


Reminder: The fundamental stages of design

user wants/needs system requirements

STAGE 1 - define the problem

STAGE 2 - develop a solution

STAGE 3 - evaluate the solution

develop a usable system for “all” users

verify/validate for all users


The fundamentals of interaction

Card, Moran and Newell (1983 – “The Psychology of Human-Computer Interaction”) proposed that actions could be described by:

Time taken = x + y + z

where = time for one perceptual cycle

= time for one cognitive cycle

= time for one motor function

x, y & z are integers

p c m

p

c

m


Putting heuristics into the design process

STAGE 1 - Problem specification

STAGE 2a - Visibility of system status• PERCEPTION

STAGE 2b - Match between system and real world• COGNITION

STAGE 2c - User freedom and control• MOTOR FUNCTION

STAGE 3 - Evaluation/verification

1

2

3

Also known as the 5-level model

See Keates and Clarkson “Countering design exclusion”

LEVEL 1

LEVEL 2

LEVEL 3

LEVEL 4

LEVEL 5


Diagrammatically…

From: Keates & Clarkson “Countering design exclusion”


The IRVIS (Interactive Robotic Visual Inspection System) prototype


Questions of interest

Question 1: Is the robot under-specified or fundamentally “wrong”? Question 2: Can we make it usable? Question 3: Can we make it accessible?


Level 1 - Problem requirements

AIM 1: What are the system requirements? AIM 2: Why did the original interface fail?

ASSESSMENT: Verify problem definition


Level 1 – Understanding the system requirements

What are the system requirements?• Understand manual process• User observations

Why did the original interface fail?

productobjectives

specificrequirements

potentialusers


The original interface


Level 1 - Problem specification (cont.)

Inspection process requires:• Translation• Rotation• Tilting• Zooming• Focusing


Developing a solution: the “Variable Fidelity Prototype”


Level 2 - Output to user – “Visibility of system status”


Level 3 - User mental model – “Match between system and real world”


Level 4 - Input from user – “User freedom and control”


Level 5 – Verifying functional and usability attributes


Level 5 - Social attributes

The design of a new interface has shown significantly increased usability

Qualitative user feedback extremely favourable The final interface also showed improved usability for able-

bodied users Costly robot re-build avoided


Features of the 5-level model

Iterative approach, with user trials and evaluation at each level Addresses each stage of the interaction process explicitly Guidelines can be incorporated where applicable Clear focus on usability


Improving the 5-level model…

Will be seen a little later…


Summary

Usability and design are closely intertwined

Usability needs to consider design perspectives

Usability methods used need to complement design process and stage of development lifecycle


Introducing “inclusive design”


The need for inclusive design - a “typical” user


The need for inclusive design - the bigger picture


What is a good/inclusive interface?

Acceptable by the intended user group

Need to define: What is the intended user group? What is acceptable?


Who are the intended users?

Typical user stereotypes The “disabled” The “elderly” The “person in the street” The “customer”


Designing inclusively = design for the disabled (?)

Need to adopt inclusive design arises because user capabilities ≠ product demands

Thus users with limited or impaired capabilities need a more accessible version to be designed

User group most commonly (stereotypically) associated with limited or impaired capabilities is people with disabilities

Ergo – designing inclusively is really designing for the disabled


Inclusive design philosophies

Most capable

Least capableTOP DOWN

Most capable

Least capableBOTTOM UP


Examples of the different approaches

AN Other Mouse

TOP DOWN BOTTOM UP

<€100>€1500


Approaches to “designing for the widest possible range of users”

Universal Design Design for All Universal Access Inclusive Design Countering Design Exclusion Design for disability


Universal Design

For a long time the most famous “inclusive design” approach Very popular in Japan and USA Strong association with architectural design

• Buildings access

Not big in Europe• “Guiding principles” seen as too rigid and too deeply associated with its US

heritage


The 7 guiding principles of Universal Design

1 - Equitable use• The design must be useful and marketable to people with diverse abilities

2 - Flexibility in use• The design accommodates a wide range of individual preferences and abilities

3 - Simple and intuitive• Use of the design is easy to understand, regardless of the user’s experience,

knowledge, language skills or current concentration level

4 - Perceptible information• The design communicates necessary information effectively to the user,

regardless of the ambient conditions or the user’s sensory abilities


The 7 guiding principles of Universal Design

5 – Tolerance for error• The design minimises hazards and the adverse consequences of accidental

or unintended actions

6 – Low physical effort• The design can be used efficiently and comfortably and with a minimum of

fatigue

7 – Size and space and approach for use• Appropriate size and space is provided for approach, reach, manipulation

and use regardless of user’s body size, posture or mobility


Other approaches to designing for the most possible users

Design for All• An older approach, very popular at one time

Inclusive design• Popular in Europe• More flexible approach than Universal Design

Universal Access• “Inclusive design for HCI”

Countering design exclusion• Developed by Keates and Clarkson (see book of same name)


Design for All(?)

Synonymous with “one product for all” (note – incorrectly)• Not really a feasible goal (see first lecture)

EU eEurope initiative defines DfA as:• “…designing mainstream products and services to be accessible by as

broad a range of users as possible.”


Defining “inclusive design” (source: Keates “Designing for accessibility”)

UK Department of Trade and Industry:• Inclusive design is a process whereby “…designers ensure that their

products and services address the needs of the widest possible audience.”

RSA (Royal Society for the Encouragement of Arts, Manufacture and Commerce):• Inclusive design is “… about ensuring that environments, products, services

and interfaces work for people of all ages and abilities.”

UK Design Council:• “Inclusive design is not a new genre of design, nor a separate specialism,

but an approach to design in general and an element of business strategy that seeks to ensure that mainstream products, services and environments are accessible to the largest number of people.”


Countering design exclusion (CDE)

Defined in BS7000 Part 6:• Design exclusion is the “…inability to use a product, service or facility, most

commonly because the needs of people who experience motor, sensory and cognitive impairments have not been taken into account during the design process.”


CDE philosophy

If you can identify who cannot use the product and why, then you know what to focus on fixing

More practical approach than “design for a wide variety of users (but we’re not going to tell you who and how many) in a wide variety of circumstances (ditto)”


What is exclusion?

Wholepopulation

Includedpopulation

Increasingsensory

capability

Increasingmotion

capability

Increasingcognitivecapability

Excludedpopulation


Where does exclusion come from?


Where does design exclusion come from?

“Designers design for themselves”

Examples to follow…

Design trade-offs…


Limits to inclusion - trade-offs


An example compromise


People are excluded based on their capabilities (DFS)

• locomotion • hearing

• reach and stretch • vision

• dexterity

• intellectual functioning • communication

and the demands made by the product

How are people excluded?

SENSORY

COGNITIVE

MOTION


Quantifying exclusion

We will look at how to measure and report exclusion in later lectures

You will see examples in the reading material for this week


Prevalence…


Where to look for prevalence data

The charities• RNIB, NFB, AFB, RNID, etc.

Lots of really useful information and data• e.g. http://www.rnib.org.uk/xpedio/groups/public/documents/publicwebsite/public_researchstats.hcsp

Great info about causes and symptoms

Question: Are these unbiased sources of data?


Charities and prevalence data

Difficult to tell how unbiased data is

Best sites cite independent studies

Others mention figures with no (or dubious) attributions

Need to treat such data cautiously

Better to rely on “official” sources, e.g. government bodies


Defining “disability” - WHO


Prevalence of “disability” in US (source: US Census Bureau 1999-2004 American Community Survey)

Respondents: 16+ % of Total 220,073,798

Margin of Error ±129,242

With any disability 16.0 ±0.1

With a sensory disability 4.7 ±0.1

With a physical disability 10.6 ±0.1

With a mental disability 5.2 ±0.1

With a self-care disability 3.1 ±0.1

With a go-outside-home disability 4.9 ±0.1

With an employment disability 5.6 ±0.1


Multiple capability losses in US (source: US Census Bureau 1999-2004 American Community Survey)

Respondents: 5+ % of Total 264,965,834

Margin of Error ±65,181

Without any disability 85.7 ±0.1

With one type of disability 6.7 ±0.1

With 2 or more types of disabilities 7.6 ±0.1

We will look at the implications of multiple impairments later…


UK Disability Follow-Up Survey

Follow-up to 1996/7 Family Resources Survey 7500 respondents 13 separate capabilities identified as important to independent living 7 relevant for product design:

• Locomotion• Reach and stretch• Dexterity• Seeing• Hearing• Communication• Intellectual Functioning

We will look a lot more closely

at this next week


Mapping to interaction models

Motor = locomotion, reach & stretch, dexterity

Sensory = seeing, hearing

Cognitive = communication, intellectual functioning


UK Disability Follow-Up Survey (Grundy et al, 1999)

Loss of capability No. of GB 16+ population

% of GB 16+ population

Motor 6 710 000 14.3%

Sensory 3 979 000 8.5%

Cognitive 2 622 000 5.6%

Motor only 2 915 000 6.2%

Sensory only 771 000 1.6%

Cognitive only 431 000 0.9%

Motor and sensory only 1 819 000 3.9%

Sensory and cognitive only 213 000 0.5%

Cognitive and motor only 801 000 1.7%

Motor, sensory and cognitive 1 175 000 2.5%

Motor, sensory or cognitive 8 126 000 17.3%


Disability Follow-up summary

8,582,200 adults in GB have a disability• 17% of the total population (1 in 6)

Of these: 34% had mild impairments 45% had moderate impairments 21% percent had severe impairments

49% had more than one impairment type

48% of disabled population is over 65 29% of disabled population is over 75


Importance of ageing

Population is getting older

50

40

30

20

10

01901 1931 1961 1991 2021

60

0 - 14

15 - 29

30 - 49

50 - 69

70 +

Year

UK

p

opu

latio

n

(mill

ions

)


It’s not just blindness

Traditionally most “accessibility” approaches for HCI have focused on blindness

Reasons: Very “visible” difficulty Very easy to simulate

• Switch off the monitor

Very effective lobbying group


WCAG 1.0 and 2.0

Look through the WCAG guidelines:

How many address vision issues (specifically blindness)?

How many address motor issues?

How many address cognitive issues?

How many address hearing issues?

Answer: Most

Answer: Some

Answer: Few

Answer: Few


Problem with focus on blindness

From DFS: 1.93 million people have vision impairment Only 20% of those are “blind”

• Need screen readers, etc.

80% are “low vision”• Need screen magnification

c.f. 2.9 million people with hearing impairments …and 6.7 million with motor impairments


Sensory impairments – Classes of impairment

Vision• Blindness – cannot see “at all”• Low vision – cannot see well• Colour blindness – cannot see all of the colour spectrum

Hearing/auditory• Deafness – cannot hear “at all”• Low hearing – cannot hear well


Cognitive impairments – Classes of impairment

Poor long-term memory Poor short-term memory Dementia – e.g. Alzheimer’s Language “deficits” – e.g. below chronological reading age Reading difficulties – e.g. dyslexia Behavioural/attentional difficulties – e.g. ADD, ADHD


Motor impairments – Classes of impairment

Restricted range of motion Tremor Spasm Poor co-ordination Limited strength Poor fine movement Poor ballistic movement


Exercise


Exercise – part 1

Each group will be assigned a type of website• Group 1 – car rental sites (e.g. Avis, hertz, alamo, budget)• Group 2 – airline flight booking sites (e.g. flysas, virginatlantic, ba, sterling)• Group 3 – travel insurance sites (e.g. columbusdirect)• Group 4 – luggage (e.g. tumi)• Group 5 – clothing (e.g. versace, lacoste)

You must look at a minimum of 3 sites

For each website, use CynthiaSays (http://www.contentquality.com/) to examine the reported accessibility of each site (WCAG Priority 1, 2 & 3)


Exercise – part 2

Use Nielsen’s heuristics from last week’s exercises to estimate the usability of each site

Question: Is there any relationship (correlation) between the overall usability and accessibility of the sites (as measured here)?

Prepare a 5 minutes presentation for Friday morning with your answer to the above question

No report needed for this exercise!

usability and accessibility lecture 5 – 02/03/10

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