© Simeon Keates 2009 Usability with Project Lecture 9 – 07/10/09 Dr. Simeon Keates.

© Simeon Keates 2009

Usability with ProjectLecture 9 – 07/10/09Dr. Simeon Keates


Exercise – part 1

Last week you were asked to make your websites accessible

Most common automated validation tool issues:• Missing ALT text• Missing FORM LABELS• Use of tables for layout• Not enough CSS• Javascript


Exercise – part 2

Other issues:• Keyboard only access (how many TAB key presses)• Depth vs. breadth• Fitts’ Law (small targets)• Cognition (learning/navigating the products)

Not really addressed by the automated tools…


Quantifying exclusion


How are people excluded?

For example, dexterity:

• can pick up items, turn handles and control switches with one hand but not the other

• has severe difficulty utilising products (i.e.: picking and pouring a full kettle)

• cannot pick up a cup or turn a handle with either hand


Users Capabilities

Physical Attributes

Information requirements

Ergonomic Features


Information available

For capabilities:

Great Britain Follow-up Survey (Grundy et al., 1999)

Thirteen capability scales ranging from

• 0 (fully able) through

• 0.5 (minimal impairment) to

• 12.5 (most severe impairment)


Typical capability scale


Disability score

• Weighted disability score = worst

+ 0.4 second worst

+ 0.3 third worst

• Score then mapped to a ten point severity category


Severity category


For physical attributes:

Adult data (Peebles and Norris, 1998)

Older adult data (Smith et al., 2000)

Information available


Product assessment

1

2

3Review


A three level approach:

Review the ideal product

Review the requirements

Review the actual product

Product assessment


A four-step review process:

Specify the context of use

Assess physical attributes

Assess capability demands

Eliminate multiple counting

Product assessment


A case study - the kettle

(a) An early kettle (b) Corded kettle (c) Cordless kettle


Consider the following example:

The ideal product demands no more than drinking from a cup

The actual product is a metal cordless kettle

The requirements suggest a lighter, smaller kettle is possible

A case study - a kettle


In this case it will be assumed that:

The kettle will be positioned to suit the height and mobility of the user

The actions required will be to fill the kettle with water, switch it on and to pour the boiling water into a cup

Specify the context of use


In this case it may be assumed that:

Hand and finger size have no significant impact on the users’ ability to use the products

Assess physical attributes


Assess capability demands



-2

0

2

4

6

8

10

-2 0 2 4 6 8 10Sensory Capability

Mot

ion

Cap

abili

ty

Scale:

1m

Full Capability



-2

0

2

4

6

8

10

-2 0 2 4 6 8 10Sensory Capability

Mot

ion

Cap

abili

ty

Scale:

1m

Full Capability

Product

demands


Assessment summary


Why quantify?

• A better product is a more inclusive product

• Or a more inclusive product is a better product?

• Hence managers and designers need be able to evaluate the inclusive merit of their products

Summary


• We can quantify exclusion

• We can identify sources of exclusion

• Thus, we can counter exclusion

Summary


• Q - The death of “inclusive” design?

– Is it possible to design to ‘include’ users?

• Q - What level of exclusion is reasonable or acceptable?

• Q - Cannot or will not?

Some questions to ponder...


Building a business case for inclusive design



Population is getting older “1 in 6” people has a “disability”• GB Disability Follow-Up Survey, US American Community Survey

Inclusive design is good design Relying on 3rd party technologies is bad business Inclusive design best practices are becoming standardised• BS7000-6

Accessibility is becoming a hot topic• ODF


Building a business case for accessibility

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

)




e.g. US Census Bureau figures• 2004 American Community Survey

Respondents:

Population aged 5 and over

Percent of total

264,965,834

Margin of error

± 65,181

With no disability 85.7 % ± 0.1

With one type of disability 6.7 % ± 0.1

With 2 or more types of disability 7.6 % ± 0.1

Remember these numbers!



Population is getting older “1 in 6” people has a “disability”• GB Disability Follow-Up Survey, US American Community Survey• Forrester Research for Microsoft…• http://www.microsoft.com/enable/research/phase1.aspx


Forrester Research for Microsoft

Among working-age adults:

27% have a visual difficulty or impairment. 26% have a dexterity difficulty or impairment. 21% have a hearing difficulty or impairment. 20% have a cognitive difficulty or impairment 4% have a speech difficulty or impairment.



For the top three difficulties and impairments: 16% (27.4 million) of working-age adults have a mild visual difficulty or

impairment 11% (18.5 million) of working-age adults have a severe visual difficulty

or impairment. 19% (31.7 million) of working-age adults have a mild dexterity difficulty

or impairment 7% (12.0 million) of working-age adults have a severe dexterity

difficulty or impairment. 19% (32.0 million) of working-age adults have a mild hearing difficulty

or impairment 3% (4.3 million) of working-age adults have a severe hearing difficulty

or impairment.



Likelihood to Benefit from the Use of Accessible Technology by Type of Difficulty/Impairment among Working-Age Adults



38% (64.2 million) of working-age adults are likely to benefit from the use of accessible technology due to mild difficulties and impairments.

22% (37.2 million) of working-age adults are very likely to benefit from the use of accessible technology due to severe difficulties and impairments.

40% (67.6 million) of working-age adults are not likely to benefit due to no or minimal difficulties or impairments.

60% (101.4 million) of working-age adults are likely or very likely to benefit from the use of accessible technology





Accessibility is becoming a hot topic Legal requirements


Legal requirements – Section 508 of 1973 Rehabilitation Act (Amended 1998 to Reauthorized Rehabilitation Act)

Applies to US Federal Govt and all of its agencies Prohibits purchasing, using, maintaining or developing any electonic

and information technology products that are not fully accessible

Single largest purchaser of E&IT equipment in the world Has become de facto accessibility standard in US

Principle is being copied worldwide


Legal requirements – 1973 US Rehabilitation Act

Established a baseline for prohibiting discrimination on grounds of disability:• In programmes conducted by Federal agencies• In programmes receiving Federal financial assistance• In Federal employment• In the employment of Federal contractors

Act was amended in 1992 and 1998


Legal requirements – 1990 Americans with Disabilities Act

Civil rights legislation Prohibits discrimination against disabled people in:• Employment• State and local government• Telecoms• Commercial facilities• Transportation• Public accommodations

Question whether “public accommodations” includes WWW…


Legal requirements – Section 255 of 1996 US Telecommunications Act

Move away from focus on US citizens being prevented from exercising their civil rights

…to ensuring that they have equal access to technology Stipulates that all US telecoms equipment is:• “…designed, developed and fabricated to be accessible to and usable by

individuals with disabilities, if readily achievable.”

Section 255 is fundamentally different to ADA and Rehab Act• A company can be found to be in breach without a complaint having to be

filed by someone who feels discriminated against


Legal requirements – 1985 Canadian Human Rights Act

Prohibits discrimination of all types Applies to:• Federal departments, agencies and Crown corporations• The post office• Chartered banks• Airlines• Television and radio stations• Inter-provincial communications and telephone companies• Inter-provincial buses and railways• Other federally-regulated industries


Legal requirements – 1996 UK Disability Discrimination Act

Addresses rights of people with disability with respect to: Employment Education • Also addressed through 2001 Special Educational Needs and Disability Act

– (SENDA)

Access to goods, facilities and services• Includes shop premises

Buying or renting land or property Public transport• HMG has power to set minimum accessibility standards


Legislation - The UK Disability Discrimination Act

“ … where any physical feature of premises occupied by the employer, or any arrangements made by or on behalf of the employer, cause a substantial disadvantage to a disabled person compared with non-disabled people, an employer has to take such steps as it is reasonable for him to have to take in all the circumstances to prevent that disadvantage … ”

In other words:

Employers must make “reasonable adjustments” to prevent discrimination


The need for accessibility - Legislation

Legislation (e.g. DDA, ADA)

Purchasing requirements (e.g. 508)

Standards (e.g BS 7000:6)

- “Exclude users only if you cannot reasonably avoid it”

- “Exclude who you like, but don’t expect us to buy it”

- “How to exclude users in the best possible way”


Building a business case - Summary

Accessibility represents a business opportunity

Accessibility challenges designers – and the best designers respond to that challenge

Accessibility needs to be an integral component of the product – and considered right from the very outset of the design process


Putting accessibility into the design process


Designing for accessibility - Key features

It is imperative that the user wants and needs for the product are identified accurately

Designing for accessibility relies on the ability to identify potential accessibility difficulties with a product

Those difficulties need to be prioritized and then fixed or removed


Designing for accessibility - Reactivity or proactivity?

Reactivity - retrospective design consideration

Proactivity - designed for accessibility

• cheap

• perceived to be easiest

• not particularly effective

• accessible products

• perceived to be expensive/difficult

• can be very effective - if done correctly


Designing for accessibility - Identifying causes of exclusion

User observation• “Gold” standard, but potentially pricey

Self assessment• Fast, cheap, highly variable

Expert assessment• Depends on the expert

Simulation• More repeatable than self-assessment• Can all impairments be simulated?


Designing for accessibility - Remedying causes of exclusion

Can this feature be removed?• Do we need it?

Can this feature be changed to make it more accessible?• Can we make it bigger?

Can a complementary method of offering the functionality be added?• Can we add a second button?

Can the functionality be offered in an alternative way?• Does it have to be a button? Can it be a slider?

Can an auxiliary aid (or assistive technology) be offered to supplement to feature?• Can we persuade the user to buy another bit of kit to use this product?


Level 1 - Problem requirements

Defining the problem Original design or review? Identify user wants

Example tools Engineering Requirements Capture techniques Usability analyses of existing designs Talking to people (e.g. users, design commissioners) Sociological models


Level 2 - Problem specification

Defining the functions What should this product do?

Example approaches Workflows Task diagrams, etc.


Level 3 - Output to user

Output mechanics of system Nature of output (e.g. aural, visual) Output media (e.g. screens, speakers) Anthropometrics / ergonomics User sensory capabilities Environment

Example tools Anthropometric/ergonomic data sets Population capability data


Level 4 - User mental model

Mapping system behaviour to user expectations Content Structure Order of interaction User mental model User cognitive capabilities

Example tools Cognitive walkthrough Questionnaires / interviewing


Level 5 - Input from user

Allowing the user to control the system Nature of input (e.g. analogue, text) Input media (e.g. keyboard, mouse, buttons) Ergonomics / anthropometrics User motor capabilities

Example tools User performance trials User models (e.g. Fitts’ Law, MHP)


Level 6 - Functional attributes

Verify and validate functionality Does the system offer the required functionality? Is the system practically acceptable to the users?

Example tools Formal usability analyses & user trials Discount analyses (e.g. heuristic evaluation) Questionnaires / interviews


Level 7 - Social attributes

Verify and validate match to user wants and aspirations Is the system socially acceptable to the users? Does the user want to use it?

Example tools Formal usability analyses & user trials Questionnaires / interviews


7 level model - summary

Level 1 - Problem requirements Level 2 - Problem specification

Level 3 - Output to user Level 4 - User mental model Level 5 - Input from user

Level 6 - Functional attributes Level 7 - Social attributes


Universal Access and Royal Mail

1 in 7 Royal Mail customers “disabled”

Must comply with DDA...

… and lead by example


Case study - The Personal Information Point


Applying the 7 level approach to the PIP

Level 1 -

Level 2 -

Level 3 -

Level 4 -

Level 5 -

Level 6 -

Level 7 -

What are the system requirements?

How does the user receive information from the PIP?

Does the user understand what is happening/required?

How does the user enter information?

Does the PIP meet the functionality needs?

What is the aim of the PIP?

Does the PIP meet the stated aim?


LEVEL 1 - System aims

Objectives Introduce Royal Mail customers to technology Pathfinder for future ‘kiosks’

Users

• Typical Royal Mail customers

Design suggestions• Aims need to be more clearly defined


LEVEL 2 - System requirements

Objectives

Not really defined!!! Reduce queue length Improve customer service DDA compliant

Users

• Typical Royal Mail customers

Design suggestions•Tasks and functionality need to be specified


LEVEL 3 - User output

Concept system Visual video footage - LCD screen Audio soundtrack - telephone handset

Assessment• Screen too high and not adjustable ?• Audio output not duplicated ?• Visual output not duplicated ?


Screen too high…


Screen too high

Female population (16+) = 24,125,000 Female population (65+) = 5,475,000

% excluded (16+) = 25% % excluded (65+) = 50%

Total excluded (16+) ≈ 6,000,000 Total excluded (65+) ≈ 2,700,000


Output not duplicated

Hearing: “Difficulty following a conversation against background noise”

(16+) = 1,922,000 (65+) = 1,232,000

Vision: “Has difficulty seeing to read ordinary newspaper print”

(16+) = 1,313,000 (65+) = 871,000


LEVEL 3 - User output

Concept system Visual video footage - LCD screen Audio soundtrack - telephone handset

Assessment• Screen too high and not adjustable -• Audio output not duplicated -• Visual output not duplicated -

6,000,000

1,900,000

1,300,000

Design suggestions• Lower screen with adjustable angle• Information channel duplication


LEVEL 4 - User understanding

Concept system No content at time of assessment However, planned to have National Savings products

Assessment• Not possible for this level• However, review your earlier exercise on this…

Design suggestions• Use another product for this!


LEVEL 5 - User input

Concept system 6 buttons - high position No support for user

Assessment• Need to stand ?• Reaching and dexterity ?


Input exclusions

Need to stand: “Often needs to hold on to something to keep balance”

(16+) = 3,145,000 (65+) = 1,621,000


Input exclusions

Reach and Stretch “Cannot hold one arm out in front or up to head (but can with other

arm)”

(16+) = 1,072,000 (65+) = 579,000

Dexterity “Can turn a tap or control knob with one hand but not with the other…”

(16+) = 2,921,000 (65+) = 1,451,000


LEVEL 5 - User input

Concept system 6 buttons - high position No support for user

Assessment• Need to stand -• Reaching and dexterity -

3,145,0004,000,000

Design suggestions• Offer physical support• Reduce reach and stretch requirements


LEVELS 6+7 - Evaluations

Total exclusions: (16+) = 5,661,000 (capability) + 6,000,000 (anthropometrics)

= 11,661,000 (out of 46,900,000)

= 24.8%

(65+) = 2,953,000 (capability) + 2,700,000 (anthropometrics)

= 5,653,000 (out of 9,273,000)

= 61.0%

Problem: Are we double counting???


Better calculations

We do not know how the anthropometric and capability exclusions are related• From different data sets

But we can make a simple correction We need to assume that the distributions are independent…


Better calculations

Imagine 2 random variables…

p(Type A) = 1 in 3 (i.e. ⅓) p(Type B) = 1 in 4 (i.e. ¼)

p(Type A and Type B) = p(Type A) × p(Type B)

= ⅓ × ¼

= 1 / 12 (i.e. 8.3%)


Better calculations – 16+

p(Excluded by capability) = 5.661,000 / 46,900,000

= 0.121 p(Excluded by anthropometrics) = 6,000,000 / 46,900,000

= 0.128 p(Excluded by both) = 0.121 × 0.128

= 0.015

p(Excluded) = p(Excluded by capability) +

p(Excluded by anthropometrics) –

p(Excluded by both)

= 0.121 + 0.128 – 0.015

= 0.234 (i.e. 23.4% or 10,975,000 people)


Better calculations – 65+

p(Excluded by capability) = 2,953,000 / 9,273,000

= 0.318 p(Excluded by anthropometrics) = 2,700,000 / 9.273,000

= 0.291 p(Excluded by both) = 0.318 × 0.291

= 0.093

p(Excluded) = p(Excluded by capability) +

p(Excluded by anthropometrics) –

p(Excluded by both)

= 0.318 + 0.291 – 0.093

= 0.516 (i.e. 51.6% or 4,780,000 people)


LEVELS 6+7 - Evaluations

Level 2population coverage

Level 4

populationcoverage

Level 3

Population coverage

Current design

User-awaredesign

Needing assistance

Estimatedlower bound

Estimatedupper bound


Summary

23.4% of all UK adults could not use the concept PIP 51.6% of “target” adults (65+) could not use the PIP Results verified by RNIB

Use of the 7 Level Model:

• Highlighted the deficiencies in a systematic manner• Generated design revision suggestions• Encouraged Royal Mail to insist on better accessibility for the PIP


Exercise


Exercise – part 1

Example: Consider sending an SMS or e-mail Look at one of your mobile phones … And a laptop

Perform exclusion calculations on each product using the data on:• http://www.eng.cam.ac.uk/inclusivedesign/


Exercise – part 2

Identify the common methods of interacting with the product

Identify which of the 7 DFS capability scales are involved in the interaction

Based on the DFS scales, estimate the limiting capability demand for each scale


Exercise – part 3

Report the number and %age of people excluded by each capability demand• For 16+ and 75+

Report the total number and %age of people excluded by the product• For 16+ and 75+

Prepare a 5 minute presentation to discuss:• Your exclusion calculation assumptions• Your exclusion calculation results• What were the principal causes of exclusion?• What do you think should be done to reduce the exclusion for each product?

© Simeon Keates 2009 Usability with Project Lecture 9 – 07/10/09 Dr. Simeon Keates.

Documents

Transcript of © Simeon Keates 2009 Usability with Project Lecture 9 – 07/10/09 Dr. Simeon Keates.