Chap11-Access-n-Users
Chapter 11: Web Accessibility & Users
- Accessibility Overview
- The 4 major areas of disability
- Mobility
- Vision
- Cognitive
- Hearing
Quotes:
[add Cerf quote or another quote about people with disabilities using the web] “People sometimes ask me, ‘What about accessibility? Isn’t that part of usability?” – Steve Krug
ACCESSIBILITY OVERVIEW What do we mean by accessibility In previous chapters we have discussed Universal Design and general best practices for design. In this chapter we will narrow our focus to issues particular to disability and accessibility. We will look first at what we mean by “Web accessibility,” then review statistics on disability in the U.S.; discuss the particular access issues for each disability area; and finally, we will discuss demographic trends in the U.S. and elsewhere related to aging and consider how this informs our discussion of Universal Design.
Web Accessibility vs. Usability Earlier, [I think – check on this], we discussed the differences and similarities between the concept of Web accessibility and usability. And Steve Krug asks the question directly in the second quote above – to paraphrase – accessibility a part of usability, is it not? What do you think? Let’s look at the definitions of both terms before answering. To answer this we need to first define our terms. Jacob Nielson defines usability as a “quality attribute that assesses how easy user interfaces are to use.” (Nielson - http://www.nngroup.com/articles/usability-101-introduction-to-usability/) The ISO definition, mentioned in chapter 1, is "the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use." Accessibility, on the other hand, is the design of products, interfaces and environments so that it can be used by people with a wide range of abilities, including those with disabilities. If Web accessibility is primarily about making sites usable by persons with disabilities, are we therefore talking about a special population? That distinguishes it from usability, does it not? The answer is yes and no. Yes – the population being addressed is the key difference between accessibility and usability. However, I would argue that accessibility is simply usability for persons with disabilities. [Put in quote from lab at AHEAD]. Otherwise, both are about designing websites so that the user interface can be used effectively with a minimal of frustration and effort by users. Coming back to our key theme – Universal Design is the broadening of usability to a wider audience. Therefore we need to understand the needs of our wider audience. That’s what we will do for the rest of the chapter: focus on audiences with “special needs,” audiences classified or considered persons with disabilities or impairment. I would caution you to remember that almost any accessibility consideration we discuss also has benefits for other users and other situations. Now let us begin our discussion of disability demographics.
• Disability Statistics
According to a 2010 Census survey, about 56.7 million or about 1 in 5 individuals (18.7 % of the non-institutionalized population) in the U.S. have a disability. Approximately 38.3 million (12.6% of the population) have a severe disability.
[Sidebar – problems with disability statistics] One of the things that become noticeable (and frustrating) when referencing statistics on disability is the variation found between different studies. For example, the Census Bureau report Americans with Disabilities: 2010 measures the prevalence of vision disability at about 8.1 million or 3.3%, significantly lower than the Center for Disease Control estimate – 21.2 million - used above. Why the difference? How disability is defined, the way questions are asked, sampling methods and sizes and other factors can affect statistical outcomes. Disability is not a binary (yes or no) determination, in contrast to measurements such as age or height and weight. If we know someone’s birth date, we can determine their age. Disability, on the other hand, is a continuum. Where on the scale of functioning we decide to demarcate disability will determine how many people are designated as disabled. [end sidebar]
Domains of Disability The following chart provides the breakdown of disability across four categories: vision, motor (or mobility), cognitive/intellectual, and hearing (or auditory). Populations with limited or reduced functioning in these areas are the ones most likely to face obstacles with Web access.
Disability Category Number of Individuals Percentage of Population Vision 8.1 million 3.3% Physical/Mobility 37.4 million 16.2% Mental or Cognitive Disability 10.6 million 4.4% Hearing Disabilities 7.6 million 3.1%
Let us look at each of these disabilities in more depth. [Need better transition, lead in] Vision
Vision impairments include blindness [include specific definition of legal blindness in footnote, elsewhere?], low vision or color blindness. Low vision, as defined by the Census 2010 survey is “having difficulty seeing words and letters in ordinary newsprint, even when wearing glasses or contact lenses” (pg. 8 Census 2000). Note that this definition of low vision is rather narrow – for example, color blindness would not be included under the Census survey’s definition of low vision. In addition, reading from a paper medium is easier than reading from a computer display. Individuals who may able to read a newspaper without difficulty may find reading from an LCD more problematic. Thus, the number of individuals with vision disabilities or at least vision problems are probably underrepresented by the Census survey and hence at least partly explains the discrepancy with other studies (see side bar).
Hearing
Hearing impairments include deafness or difficulty hearing. Difficulty hearing is defined as “difficulty hearing a normal conversation, even when wearing a hearing aid” (pg. 8. Census 2010).
Cognitive/Intellectual
A cognitive/intellectual disability can range from perceptual/cognitive issues such as dyslexia to ADHD to memory loss to dementia.
Physical/Mobility This can include: difficulty grasping, lifting or moving objects; difficulty walking, standing or climbing stairs; or problems with fine motor movement due to conditions such as ataxia or spasticity.
Accessibility Issues by Disability
Vision
Because the Web is primarily a visual interface, individuals with low vision or blindness are, perhaps, the demographic most often facing significant barriers accessing the Web. (Mention sidebar of initial Web).
Web Designers unfamiliar with Assistive Technology often ask if they need to provide audio output of the information on their website for blind or low vision users. The answer is a resounding “no.” Screenreader technology such as JAWS (Windows) or VoiceOver (Mac) allow voice output (the “reading” of screen text with synthesized speech) for individuals who cannot see or read the text or other objects on the screen.
Individuals with low vision may be able to read the screen through enlargement of the screen with products such as ZoomText or Magic. For some individuals, increasing the font size and/or selecting a high-contrast visual scheme through the Windows or Mac control panel is sufficient to allow effective reading and access to information displayed on the screen, whether a web page or the desktop of the computer. [Highlight box] Read an online profile of a person with blindness at the Web Access Initiative (WAI) website. (Note: the site opens with the section More about Ms. Laitinen closed by default. Be sure to open us this section. Similarly the section Text alternatives for non-text content (Perceivable) under Sections related to Ms. Laitinen.) [end: highlight box] What Can Be Read by a Screenreader? The Importance of Alternative Text.
Although screen enlargement software can enlarge both text and images, screenreader technology can read text and only images that that have been marked up with alternative text (in the context of HTML referred to as the “alt attribute”). Alternative text is a short description of the purpose of, or the information conveyed by, the image (will be discussed further in ….???). [sidebar: Google is deaf and blind billionaire]
Alternate text benefits not only blind and low vision users but also individuals with cognitive and intellectual disabilities who may use screenreader technology as well. In addition, alternative text aids search engine optimization (SEO) (see Google sidebar). Therefore, ensuring that all the non-text elements on your web pages are labeled with alternative text is the most important and easiest action you can take to make your sites accessible. Alternatively, a page filled with images without alternative text will surely make your site inaccessible to both screenreader users and search engines. As a result your site will be less “findable” with Google, Yahoo, and other search tools. [List other things you should do that we will cover in other parts of the book]
Hearing As mentioned in the sidebar, the Web, at its inception, consisted only of text (and text-based hyperlinks). Not only was the image-free environment a benefit for individuals using screenreaders, the lack of audio benefited individuals with deafness or hearing loss. With the rise of audio and multimedia on the Web, the likelihood of Deaf and Hard of Hearing individuals encountering content that they cannot access has significantly increased, particularly in the last decade. [find out when audio and multimedia first appears on the Web] For those with deafness or hearing loss, access to audio is provided through transcripts (for content which is exclusively audio) and captioning (for multimedia). Unlike alternative text for images, providing transcripts and captioning is a challenging and time-consuming undertaking which usually requires the use of a 3rd-party transcription/captioning service or an in-house individual or team dedicated to its production. [List other things you should do that we will cover in other parts of the book] (Other benefits of captioning)
[highlight box:] Read a profile of an individual with a hearing disability and adaptations required for access to the Web . (Also read the section More about Ms. Olsen) [end: highlight box]
Cognitive/Intellectual
Individuals with cognitive/intellectual issues benefit from many of the same design features or Assistive Technology mentioned for individuals with vision impairment, including screen-enlargement, voice output and high contrast color schemes. The consistent placement of navigation throughout a site and the following of best design practices also benefits both these groups (and all users for that matter). [need to reword]
[List other things you should do that we will cover in other parts of the book]
[highlight box:] Read a profile of an individual with a cognitive disability and their use of Assistive Technology. (Also read the section More about Ms. Olsen) [end: highlight box]
Physical/Mobility Individual with physical or mobility disabilities affecting their upper extremities (i.e. their arms) face issues of web and computer access, more so than for individuals with lower extremity issues. The reasons are obvious – we use our arms and hands to control the keyboard and mouse, and increasingly, a tablet or touch screen (and more recently – for gestures to control the user interface). Individuals with upper extremity limitations may use voice recognition technology such as Dragon NaturallySpeaking to input text and to interact with controls and objects on a web page; or if they lack the fine motor control for mouse use, they may rely on the keyboard alone to navigate and interact with controls on a computer or web page. [List other things you should do that we will cover in other parts of the book] [highlight box:] Read a profile of an individual with a physical/mobility disability and their use of Assistive Technology. (Also read the section More about Mr. Martinez) [end: highlight box] Suggested viewing: Working Together: Computers and People with Sensory Impairments To view a video of how individuals using different Assistive Technologies access computers and the Web, view the video at the url below. http://www.washington.edu/doit/Video/index.php?vid=31
statutory/legal blindness continues to be defined as best corrected visual acuity of 20/200 or less in the better eye; or a visual field limitation such that the widest diameter of the visual field, in the better eye, subtends an angle no greater than 20 degrees (http://lighthouse.org/about-low-vision-blindness/definition-legal-blindness/)
“Temporarily Able-Bodied
Those of us on the side of the functional spectrum considered able-bodied (i.e. non-disabled) may consider this a permanent situation, but in all likelihood this will change as you age, although hopefully later than sooner. The Census Bureau’s Americans with Disability: 2010 report offers these other rather interesting statistics:
1. 1 in 20 individuals aged 15 – 24 had a severe disability.
2. 1 in 4 individuals aged 65 to 69 had a severe disability.
3. 70.5% of the oldest age group, 80 and older, had a disability, and more than half of this group (55%) had a severe disability. (pg 5 & 6 of report).
Aging of Population Although we saw that there are differences in how various studies measure disability, one thing is indisputable when looking at disability statistics: disability prevalence increases with age. Clearly, as we age, our chances of acquiring a disability increases. The reasons for this are self-evident: our senses diminish as we age and we are more subject to degenerative diseases such as arthritis, diabetes, cataracts, heart disease and stroke. [There is a saying among the field of disability: someone either has a disability or are “temporarily abled.” [find source]] In other words, almost all of us will eventually experience a disability either through disease, accident, or the normal process of aging. (Are you depressed yet?). Even if you are one of the lucky people to die peacefully in your bed at a ripe old age without experiencing any loss of physical, sensory, or cognitive function (highly unlikely), it still behooves you to learn and incorporate UD into your Web design tool kit.
If we look at the prevalence of disabilities across age groups, we clearly see that disability increases with age – those aged 65-69 have 5 times more likelihood of having a severe disability than those in the 15–24 age range; those 80 and over have 10 times the likelihood. With the aging of the baby-boomers, by 2030, 19% of the population will be over 65 compared with 13% in 2010. The implications for disability are clear – we will very likely have an significantly increased percentage of those with disabilities.
As we discussed in chapter 1, the aging of the population is part of the impetus for Universal Design.
[Include World Wide Stats]
