Fundamental Principles and Priority Setting for Universal Usability Gregg C. Vanderheiden Ph.D. Trace R& D Center Depts. of Ind. Engr & Biomed. Engr University.

Fundamental Principles and Priority Setting

for Universal Usability

Gregg C. Vanderheiden Ph.D.Trace R& D Center

Depts. of Ind. Engr & Biomed. EngrUniversity of Wisconsin – Madison

What Is Universal Usability

Based on Universal Design definition….

Universal Design is theprocess of designing products so that they are usable by the widest range of people - operating in the widest range of situations as is commercially practical.

Not just people with disability

In fact for every disability there are situations that people without disabilities would encounter that would yield the same interface requirements

For example ---

Operable without vision

- people who are blind

- people whose eyes are busy(e.g., driving your car or phone browsing)- who are in darkness.

Operable with low vision

- people with visual impairment

- people using a small display - or in a smoky environment.

Operable with no hearing

- people who are deaf

- people in very loud environments - or whose ears are busy- or are in forced silence (library or meeting).

Operable with limited hearing

- people who are hard of hearing

- people in noisy environments.

Operable with limited manual dexterity

- people with a physical disability

- people in a chemical or space suit - or who are in a bouncing vehicle

Operable with limited cognition

- people with a cognitive disability

- people who are distracted - or panicked - or under the influence of alcohol.      

Operable without reading

- people with a cognitive disability

- people who just haven't learned to read ‘that’ language, - people who are visitors, - people who left reading glasses behind

Reasons for Increased Interest

Aging of the population and relation between aging and functional limitations

Graying of America

0

5

10

15

20

25

30

35

19001910192019301940195019601970198019902000 20102020203020402050

85 up

75 to 84

65 to 74

55 to 64

Sources: 1900-1980: U.S. Bureau of the Census, Decennial Censuses of Population. 1990-2050: U.S. Bureau of the Census, Projections of the Population of the United States, by Age, Sex and Race: 1983 to 2080. Current Population Reports, Series P-25, No. 952, May 1984. Projections are middle series.

(percentage of the population over age 55 as a function of time)

The Graying of AmericaThe Graying of America

2000

Functional Limitation as a Function of Age

Prevalence of Selected Impairments

Trace R&D Center, University of Wisconsin

Prevalence of Selected Impairments within Age GroupsPrevalence of Selected Impairments within Age Groups

0

10

20

30

40

50

60

70

Arthritis& Bursitis

Back & Spine

Other Physical

Impairments

Speech Impairments

Visual Impairments

Hearing Impairments

Mental Retardation

Diabetes

Based on data from LaPlante (1988) Survey: National Health Interview Surveys, 1983-1985: tabulations from public use tapes

% of age group

Under 45

45-69

70-84

85+

(Data categories are not exclusive)

Reasons for Increased Interest

ADA Section 255 Section 508 States and Companies interested in products which

are more usable by their employees with disabilities and those that are aging

Aging of the population and relation between aging and functional limitations

In Looking at Accessibility

Need to set priorities – for features to implement – – where to focus efforts.

Because of – The multidimensional nature of disability– The large number of things that can be done

• Studied over 1000 different strategies• We’ve identified between 200-300 unique strategies

Some things are essential, some are important, some are just nice.

Also, industry can’t go from 0-60 mph instantly Need to know where to focus efforts

– What is most important to each disability type, combination

Risks From NOT prioritizing

– Designers are overwhelmed and lock up.– Usability testing is tried but

• Problem getting all the different disability types / combinations involved. • Also generates long list that still needs to be prioritized

– Designer start doing what is easy or looks good• Unimportant gets implemented while critical is unattended

– Spend time patching all the superficial wounds will person bleeds to death internally. They know about it but it is much harder to do.

• Solomon’s Trap

Danger FROM prioritizing– If done on population size, then low priority items for large

populations are addressed while critical, easy to do items for low priorities are overlooked.

Problem is multidimensional. Need to consider several dimensions at the same time. No one prioritization scheme is sufficient.

Everything should be made as simple as possible. But no simpler. 

A. Einstein

Some Dimensions

Accessibility – Usability Independence vs Co-dependence Efficiency and Urgency Requirement Ease of Implementation

Accessibility/Usability

© 1999 Trace R&D Center, University of Wisconsin

First dimension for prioritization – Accessibility/Usability

Level 1 – features which, if they have not been implemented, will cause a product to be unusable for certain groups or situations.

Level 2 – features which, if not implemented, will make the product very difficult to use for some groups or situations.

Level 3 – features which, if they are implemented, will make the product easier to use but do not make a product usable or unusable

– (except for individuals who are just on a margin due to other factors and this small amount of usability pushes them over the threshold).

The second dimension - Independence vs Co-dependence

1. Functions/features needed for basic use of the product

2. Unpredictable, but typically user-serviceable (by "average" user) maintenance or recovery operations

3. Unpredictable service, maintenance or recovery, typically corrected by support personnel

4. Predictable or schedulable  maintenance that can be delegated to others

5. Unpacking and initial setup

6. Repair

NOTE: The location and availability of support personnel (e.g. in a home office) affect this dimension.

A third dimension - Efficiency and Urgency Requirement

Is the task performed only once a day How long does the task take It is a timed operation Any consequences from slower operation

– Are the reversible

– Are they severe

Examples– Typing on keyboard (high)

– Operating computer “ON” switch quickly (low)

– Entering code on Entry Security Keypad• Quick entry – low (ok to be slower than average)

• Quick enough to prevent tripping alarm – high

A Pseudo Priority Dimension – Ease of Implementation

“low hanging fruit” Listed because important consideration in

allocation of resources Listed as Pseudo because it really shouldn’t

be used in setting priorities, though it may be used in implementation decisions.

Danger is that Easy things start being done rather than important (Remember early slide on this issue)

Recommendation Do not use “Ease” in setting priorities. Create your priority list without the “Ease” factor –

and keep the list as your focus. Then take “Ease” into consideration as you pick

things off your priority list to implement.

Remember that “opportunity” (a close relative of “ease”) will often be a bigger factor (and affects ‘ease’). Opportunity however is often fleeting and revising your priority list based on this is often not practical or smart.

Or in other words….

“Keep your eyes (and priority) on what is important – and take advantage of opportunities to to address them as you can – but always push for (and make opportunities for?) the most important on the list.”

Underlying fundamentals of information technology access.

On going effort by a number of us internationally.

One pass is presented in the proceedings Goal was to get on one page, the essentials

Basics

Make all information perceivable (including key & control -status & labels)

Provide as least one mode for all product features that is operable

Facilitate Navigation Facilitate Understanding of Content Compatible with Assistive Technologies

commonly used by people

Make all information perceivable (including key & control -status & labels)

Without vision Without hearing Without reading (low vision or cognition) Without color perception Without causing seizure

Provide as least one mode for all product features that is operable

Without pointing Without vision Without requirement to respond quickly Without fine motor movement Without simultaneous action Without speech Without requiring presence or use of

biological parts (touch, fingerprint, iris, etc.)

Facilitate Understanding of Content

Without skill in language used on product Without good memory Without background

Facilitate Navigation

Without sight Without pointing ability Without find motor control Without prior understanding of the content Without the ability to hear

Ease of Implementation