© simeon keates 2009 usability with project lecture 9 – 07/10/09 dr. simeon keates
TRANSCRIPT
© Simeon Keates 2009
Usability with ProjectLecture 9 – 07/10/09Dr. Simeon Keates
© Simeon Keates 2009
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
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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…
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Quantifying exclusion
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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
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Users Capabilities
Physical Attributes
Information requirements
Ergonomic Features
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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)
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Typical capability scale
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Disability score
• Weighted disability score = worst
+ 0.4 second worst
+ 0.3 third worst
• Score then mapped to a ten point severity category
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Severity category
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For physical attributes:
Adult data (Peebles and Norris, 1998)
Older adult data (Smith et al., 2000)
Information available
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Product assessment
1
2
3Review
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A three level approach:
Review the ideal product
Review the requirements
Review the actual product
Product assessment
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A four-step review process:
Specify the context of use
Assess physical attributes
Assess capability demands
Eliminate multiple counting
Product assessment
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A case study - the kettle
(a) An early kettle (b) Corded kettle (c) Cordless kettle
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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
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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
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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
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Assess capability demands
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Eliminate multiple counting
-2
0
2
4
6
8
10
-2 0 2 4 6 8 10Sensory Capability
Mot
ion
Cap
abili
ty
Scale:
1m
Full Capability
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Eliminate multiple counting
-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
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Eliminate multiple counting
-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
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Assessment summary
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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
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• We can quantify exclusion
• We can identify sources of exclusion
• Thus, we can counter exclusion
Summary
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• 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...
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Building a business case for inclusive design
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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
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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
)
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© Simeon Keates 2009
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
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© Simeon Keates 2009
Building a business case for accessibility
Population is getting older “1 in 6” people has a “disability”• GB Disability Follow-Up Survey, US American Community Survey
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!
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Building a business case for accessibility
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
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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.
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Forrester Research for Microsoft
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.
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Forrester Research for Microsoft
Likelihood to Benefit from the Use of Accessible Technology by Type of Difficulty/Impairment among Working-Age Adults
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Forrester Research for Microsoft
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
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Forrester Research for Microsoft
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© Simeon Keates 2009
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
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© Simeon Keates 2009
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 Legal requirements
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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
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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
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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…
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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
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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
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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
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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
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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”
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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
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Putting accessibility into the design process
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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
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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
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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?
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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?
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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
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Level 2 - Problem specification
Defining the functions What should this product do?
Example approaches Workflows Task diagrams, etc.
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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
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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
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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)
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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
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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
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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
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Universal Access and Royal Mail
1 in 7 Royal Mail customers “disabled”
Must comply with DDA...
… and lead by example
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Case study - The Personal Information Point
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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?
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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
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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
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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 ?
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Screen too high…
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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
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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
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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
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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!
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LEVEL 5 - User input
Concept system 6 buttons - high position No support for user
Assessment• Need to stand ?• Reaching and dexterity ?
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Input exclusions
Need to stand: “Often needs to hold on to something to keep balance”
(16+) = 3,145,000 (65+) = 1,621,000
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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
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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
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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???
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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…
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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%)
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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)
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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)
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LEVELS 6+7 - Evaluations
Level 2population coverage
Level 4
populationcoverage
Level 3
Population coverage
Current design
User-awaredesign
Needing assistance
Estimatedlower bound
Estimatedupper bound
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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
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Exercise
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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/
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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
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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?
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