PowerMapper Software Blog

This post  follows on from the one on Disability Statistics, and shows how the most common disabilities affect website use.

Reading Difficulties

Reading difficulties and dyslexia are extremely common, and affect 15-20% of US adults. Some groups (such as entrepreneurs) have rates approaching 40%.

This group often finds problems with:

• large blocks of text
• very high contrast text*, such as black text on pure white affects people with Scoptic Sensitivity Syndrome (which makes the letters dance about)
• fully justified text aligned to both left and right margins (contains rivers of whitespace which break up the text)
• flashing or moving elements, which attract the eye and make it hard to concentrate on reading text  

* Note that the high contrast required by WCAG 2 checkpoint 1.4.3 can actually cause problems for people with Scoptic Sensitivity Syndrome, and also some low vision users who need to read the screen very close up (put your face next to your screen for 30 minutes on a very high contrast page to see how unpleasant this feels). 

Color Blindness

Color blindness is also very common, and affects around 8% of caucasian males in the US, but only 0.5% of females. Color blindness comes in many varieties with red-green and blue-yellow color blindness the most common, and inability to see any colors (monochromacy) the rarest.

This group often finds problems with:

• text and background colors with little difference in brightness 
• red text on a green background, or green text on a red background (looks like brown text on a brown background to someone with red-green color blindness)
• blue text on a yellow background or yellow text on a blue background  

Dexterity Difficulties

Problems using hands and arms affects around 7% of the population, and can make using a mouse hard or impossible. Older people are more likely to have dexterity problems due to the onset of arthritis. Even if users can use a mouse, they'll find it hard to click on small link targets (such as single character links).

This group often finds problems with:

• pages that can only be operated with a mouse (e.g. many street mapping websites)
• very small links that need very precise motor control to click (e.g. the single character links often used for paging)    

Difficulty Hearing

This affects around 4-5% of the population, and becomes more common with age. Relatively few websites use audio, so the majority of sites are unaffected. Many office workers are in the same position, since they have no way of hearing website content at work (speakers are very uncommon in offices, and headphones are frowned upon in some corporate settings). 

This group often finds problems with:

• videos where the audio track is needed to understand the content (e.g. a recording of a TV news bulletin) 
• standalone audio (e.g. a radio play)   

Difficulty Seeing

This affects around 3-4% of the population and includes people who are blind and those with low vision who need large print and/or high contrast to read (e.g. people with cateracts or retinal damage caused by diabetes). 

Blind people (and some dyslexics) typically use a screen reader, which read out the words on web page, but reading each word out individually is very time consuming so:

• they use the <title> tag to find out what a page is about before going to the effort of reading it (so the same title on every page is not useful)
• they often read out all the headings and link text first to figure out what a page is about (screen readers have shortcut keys for this)
• the use headings inside the page to navigate to the section they're interested in (so pages without headings are hard to use)
• they need a quick way to skip navigation links at the top of the page (you don't want to have to listen to 100 navigation links before hearing the page content)  

People with low vision:

• often use browser zoom feature to enlarge all the content (normal text enlarges well, but text inside graphics becomes pixelated)
• may use a custom CSS stylesheet to enlarge text and provide color combinations that work for them (e.g. 24 point yellow text on a black background). This poses difficulties if your pages are unreadable without your site's CSS stylesheet.

Well, it’s that time of year again. While I consider myself one of life’s formidably organised Christmas present buyers (I started in August) I seem to fall sadly short when it comes to finding the time to write and post my Christmas cards.

I know that to many, card writing seems an outmoded way of sending Christmas greetings, but for many of my ageing relatives, some of whom now live alone, a hand written card arriving in the mail is still much appreciated. Besides, I still enjoy choosing the cards - I fancy I always find something pretty tasteful!

Recently, a close friend paid me a compliment which really cheered me. Her mother has very limited vision - she's been registered blind for as long as I’ve known her. When choosing her card, I’ve always made certain that the design is simple, bold and very colourful. To me that just makes common sense. Surprisingly, few others do, and my friend tells me that her mother always enjoys my card arriving in the mail - it’s one of the few she can see. 

Since accessibility plays a large part in what we do here, I was pleased to know that I was practising what we preached. 

This posting summarizes some detailed research into the state of government accessibility standards around the world, as of September 2011. Usually these evolve fairly slowly, although the recent Jodhan vs. Attorney General of Canada case may change that (governments don't like being successfully sued by their citizens).

This table shows government accessibility standards, and relevant legislation, in 11 countries:

* Irony Alert: the European resolution insists web site documents should be clear and simple, but kicks off with 22 paragraphs of incomprehensible bureaucratic text. Here's an example:

whereas the internet as a part of society is an instrument for society as a whole, so it is fundamental that technologically neutral access to public information is offered for all groups in society...

The key takeaway from this research: adoption of WCAG 2 is progressing steadily and becoming increasingly important:

• The Australian, French and New Zealand governments have already adopted WCAG 2.
• The Jodhan vs. Attorney General of Canada ruling means the Canadian government is required to adopt WCAG 2.
• UK government sites must comply with either WCAG 1 AA or WCAG 2 AA.
• In the US, Section 508 is being refreshed to harmonize with WCAG 2.
• The European Commission is investigating a move to WCAG 2 as a European government standard, but this is complicated by competing national standards in Germany (BITV) and Italy. 

Edit: originally published November 2010, updated November 2011.

Today is World Stroke Day, which aims to raise awareness of the condition. Earlier this week I saw a conference keynote speech by Clayton Christensen, author of The Innovators Dilemma and a Professor at Harvard Business School.

He introduced himself by apologizing for hesitating while speaking because he'd suffered a stroke a few months earlier. In spite of this he was an engaging speaker - much better than the other professional conference speakers. His points came across so well because he's been thinking about them for decades and backed them up with well-researched evidence. His only concession was asking the audience to interject when he couldn't remember a word, but this made the presentation more interactive and memorable.

At the end of the day having something important to say always beats slick presentation.

This post is a compilation of disability statistics from government agencies and researchers in the US, UK and Canada. The statistics shown have most impact on website use, and help assess the impact of accessibility problems, in terms of numbers of people affected, and likely commercial impact.

Incidence of Key Disabilities

Reading Difficulties		15%-20% of people in the US have reading difficulties, including dyslexia (source: nih.gov). A recent study by Cass Business School showed that around 20% of UK entrepreneurs and 35% of US entrepreneurs are dyslexic (Bill Gates and Richard Branson are textbook examples).
Color Blindness		8% of males in the US suffer from some form of color blindness, compared to 0.5% of females. (source: aao.org). Incidence of color blindness differs between ethnic groups - from 1% in Eskimos to 10% in Caucasian males.
Dexterity Difficulties		7% of working age adults have a severe dexterity difficulty (source: The Wide Range of Abilities and Its Impact on Computer Technology - Microsoft / Forrester). Severe dexterity difficulties mean users are unlikely to use a mouse, and rely on the keyboard instead.
Difficulty Hearing		4%-5% of people in the US, UK and Canada suffer from difficulty hearing (sources: census.gov, Statistics Canada, UK ONS) Incidence increases sharply in over-60s, with more than 20% of over-75s affected.
Difficulty Seeing		3%-4% of people in the US, UK and Canada can't see well enough to read (sources: census.gov, Statistics Canada, UK ONS) Incidence increases with age, with more than 10% of over-70s affected.

Note: Government statistical agencies produce these numbers from questionnaires, but questions aren't standardised between countries, so figures are not directly comparable from country to country. For example, the questions "do you have difficulty seeing" and "do you have difficulty seeing newsprint" produce different response rates.

Incidence of Disability by Age

Hearing and sight becomes poorer as people get older, but these same people often have large amounts of disposable income and leisure time. This presents particular challenges for web sites selling items which appeal to an older demographic, such as travel and cruises (source: census.gov).

The Design for All Research Group at Middlesex University have produced a report called Declaring conformance on web accessibility asking the question: can website accessibility declarations be trusted?

Sadly the conlusion was no, for both self-declared and thirdy-party certifications, confirming the findings of earlier studies. Using a sample of 100 European government and commercial sites claiming accessibility standards conformance, more than 95% were found to have accessibility issues. The study used our automated tool, SortSite, in conjunction with manual testing performed by the accessibility group at the Shaw Trust (see the report for details on methodology).

The results on accessibility conformance mirror results we see with sites claiming to be valid HTML. About 30% of sites displaying the W3 "Valid HTML" and "Valid XHTML" badges fail validation. Although false validation claims are a smaller proportion than false accessibility claims, it's more surprising since:

• the validation test is completely automated so should be easy to run
• using the W3 "Valid HTML" badge on invalid pages is a breach of the W3's terms of use

In practice ensuring entires sites are accessible and conform to standards is tough to do manually. Even a medium sized site with 10,000 pages takes over 200 days to test manually, assuming an 8 hour working day, and 10 minutes spent testing each page for accessibility and web standards compliance. To underscore this point, the original version of the report was published as an untagged PDF, making it hard to use in a screen reader. A quick run through an accessibility checklist or automated checking tool could have prevented this.

A few days ago I attended a presentation given by some UK Government departments - the main topic was providing equality of access to government contracts. There was the usual torrent of PowerPoint slides filled with facts, figures and addresses of websites which publish government contracts. 

At the end of the presentations the question and answer session started:

Chief Official: "Does anyone have any questions?"
Lady in Audience: "Will any of the slides be available after the meeting?"
Chief Official: "We'll consult on that afterwards."
Lady in Audience: "I'm blind and none of this information was accessible to me."
Chief Official: "Oh..."
Second Official: "We can translate them into PDF ... or braille."
Third Official: "I can read them out to you ... would that help?"

The officials' discomfort was very obvious, and entirely deserved.

The W3 Web Accessibility Initiative has a very good guide on how to make presentations accessible, but the key point is ask participants if they have any accessibility requirements before giving the presentation.