Thursday, April 26, 2007

Web Accessibility

The web is a dominant force today. It’s use is ever increasing and evolving simultaneously. This force should be accessible to the widest spectrum of users. However, there are forces within this force that does not permit it’s usage to it’s fullest capacity and to it’s widest ranges of users.

This paper was developed as a part of the USQ FET8610 Semester 3, 2006, Task 5. This article looks into what web accessibility is, the web disabilities, benefits of accessibility and some techniques to make an accessible website.

The Web is a useful medium of information, entertainment, communication and community (Clarke, 2002). It provides opportunities to participate in society in ways otherwise not available (Henry, 2006). Much of its power comes from the fact that it presents information in a variety of formats and methods. The challenge is to use design principles to create resources that are accessible by the widest spectrum of audiences. The problem is that most websites have accessibility barriers that make it difficult or impossible for many people with disabilities to use them or to contribute to the Web. Web accessibility is about removing those barriers so that people with or without disabilities can use and contribute to the Web. Accessibility is an essential component of a good web design (Corcoran & Corcoran, 2002). Many are standing at the shores of accessible web design, fearing sharks where there are only gentle waves (Moss, 2004).

What is Web Accessibility?
Web Accessibility refers to the designing of website which is accessible to a wide range of users. According to Wikipedia, web accessibility refers to the practice of making web pages accessible to people using a wide range of user agent software (such as web browsers and screen readers) and devices (like mobile phones and personal digital assistants). More specifically it means that people with disabilities can perceive, understand, navigate and interact with the web and can contribute to the web (W3C Web Accessibility Initiative). It enhances the usability for all users.

Issues Addressed Under Web Accessibility
Web Accessibility is aimed at addressing the physical and technological disabilities. However, as of yet there is no universally accepted categorizations of disabilities.

The physical disabilities are the inabilities to function normally, physically or mentally (The Free Dictionary) and these include:

Visual impairments including blindness, low vision, poor eyesight and color blindness.

Deafness or hearing impairments including of people who find it difficult to hear.

Difficulty or inability to use the hands/fingers including tremors, injuries to spinal cord and limbs, slowness of muscle and muscle control and due to conditions and illness (Web Accessibilty In Mind) such as the Parkinson’s disease, cerebral palsy, muscular dystrophy and others like like stroke, Lou Gehrig’s disease, spina bifida, arthritis, multiple sclerosis.

Developmental, learning and perceiving disabilities such as slow learners, cognitive disabilities of various origins affecting memory, attention, problem-solving and logic skills, reading, linguistic, verbal, math and visual comprehension disabilities.

Photo-epileptic seizures caused by visual strobe or flashing effects (Wikipedia).

Aging-Related Conditions
Old aging disabilities such as changes in abilities or a combination of abilities including vision, hearing, dexterity and memory (W3C Web Accessibility Guidelines).

The technological disabilities are the inabilities caused due to the connectivity, computer system, hardware and/or software being used. These include:

User Agent Devices & Software
Disabilities caused by the user software like Operating Systems, web browsers, media players, assistive technologies, and other software that people use to access and interact with web content. Websites works and displays differently in different web browsers (Clarke, 2002) and in different user devices. It also includes the disabilities caused by the use of other input devices to browse websites such as keyboard (Bohman,2002),wands & sticks, touch screens and joysticks (USQ knowledgeGarden).

Bandwidth & Connectivity
Disabilities caused by slow connections (Web Accessibility Initiative) and the type of connectivity such as dial up connections.

User Preferences

Disabilities caused by the user settings, preferences and different features enable or disabled (Web Matters).

Each of the categories of disabilities requires certain types of adaptations in the design of the web content (Web Accessibility Initiative). Most of the time, these adaptations benefit nearly everyone, not just people with disabilities.

Why Web Accessibility?
It is essential that web be accessible in order to provide equal access and equal opportunity to people with disabilities. While the primary focus of web accessibility is on access by people with disabilities, for a broader perspective, it can be considered that it is about designing website so that more people can use it effectively in more situations (Henry, 2006). Some of the reasons of making web accessible are:

• Increases Website Use

Accessible websites are easier to use, thus resulting in more users and increased usage. Therefore, increasing the market segments (Web Accessibility Initiative). Many organizations benefit financially when more people successfully use their website (Henry, 2006) which contradicts one of the most common accessibility myths – access is expensive (Clarke, 2002).

Improves Usability for all users
People with or without disabilities generally find accessible sites more usable. Increased usability means website users achieve their goals effectively, efficiently, satisfactorily and quickly. This leads to user retention and user acquisition (Henry, 2006).

• Supports Users with Low Literacy Level

Accessible websites supports users with low literacy level (Web Accessibility Initiative) such as those users with reading or comprehending difficulties or whose first language is not that of the site.

• Improves Search Engine Optimization
Making site accessible can significantly improve search engine optimization (Web Accessibility Initiative). Non text-based contents are not available to search-engines or other automatic data-mining applications. Text-based contents are highly likely to be picked up by the search engine spiders and thus increase the likelihood of a user finding the site. Employing accessibility techniques will most surely improve the web pages' ranking (Henry, 2006).

• Assists Users with Low Bandwidth Connectivity

By providing alternative content through following the accessibility techniques will assist users with low bandwidth connections which can lead to increase website use. Majority of the world’s users is limited to low bandwidth connections because of geographical isolation, or underdeveloped communications infrastructure (Gristock, 2003) or are forced by the economic or technical circumstances.

• Reduces Site Maintenance
Initially site development time increases when incorporating accessibility. However, in the long term, web accessibility can reduce the time and the money spent on site maintenance.

• Improves Server Performance
Web accessibility techniques improves server performances by reducing server load, increasing site download speed and imposing less strain on low bandwidth.

• Re-purposes Content for Multiple Format & Devices
In the continually evolving Web technologies, it makes sense to design web content and services that can be adapted quickly and efficiently to meet any new circumstances (Web Accessibility Initiative). Using of web accessibility techniques will require fewer adaptations to create multiple versions of site in multiple formats for multiple devices.

• Demonstrates Social Responsibility
Increasing the accessibility of website and online services to a wide range of people with disabilities will reinforce social responsibility (Web Accessibility Initiative) to the community and provide equal access and equal opportunity to people with disabilities. It also removes the perceptions from the disabled people that the web is only for the non-disabled.

• Required by Law
Antidiscrimination legislation in the most Western nations including the U.S., Canada, Australia, and the U.K. forbids discrimination or unequal treatment on the basis of disability (Clarke, 2002). Providing accessible websites and online services to people with disabilities is a form of adhering to the law.

Web Accessibility Techniques
These are guidelines, methods and standards that can be implemented in the website design to improve its usability and accessibility. Some of the web accessibility techniques are:

• Use clear and understandable content.
• Use simpler language for content rather then technical jargons. Information written simply and clearly is more accessible (Corcoran & Corcoran, 2002).
• Use a universal language for the content such as English unless the website’s intended audience prefers another language.
• Website content should be organized well (The Ohio State University Web Accessibility Center).

General Site Design & Navigation
• Maintain a simple, clear, logical and consistent design & layout throughout the site such as having a standard navigation system (Comden & Burgsthaler, 2002). This is particularly useful for users with cognitive disabilities (Simpkins, 2005).
• All links including the image links should describe its destination (Bohman, 2002). The links should use descriptive phrases (Comden & Burgsthaler, 2002) thus conveying its purpose (Bohman, 2002). Linked information should be readily accessible i.e users should be able to reach a particular page or information with few clicks (1 or 3 clicks) as possible (Sonnoff, 2006).
• Avoid broken and adjacent links.
• There should be an alternative text links if the navigation system is relying on image maps or image links (Farkas & Farkas, 2002).
• Use site maps and linked table of contents as it helps users in the quick retrieval of information.

• Keep the page background simple (Comden & Burgsthaler, 2002). Avoid busy and distracting backgrounds.
• Provide the highest color contrast between the text and the background (The Ohio State University Web Accessibility Center).
• Avoid the use of multiple colors in the site as this will be useful when the site is viewed using devices that don’t display color. Never use color alone to indicate differences between parts of the webpage (May, 2005).

• Provide text alternatives (ALT) for all images to make the content accessible (Comden & Burgsthaler, 2002). Text alternatives should be descriptive and brief (Bohamn, 2002).
• Use “D” links and “longdesc” attributes for complex images, graphs and diagrams (Web Accessibility Initiative) as it can help in conveying its purpose.
• Use a NULL value for unimportant images (Comden & Burgsthaler, 2002).
• Add captions or supplementary notes to the images.
• Images should be optimized for smaller file size as it aids users using slow connections.
• Provide text alternative version or HTML of the website if it’s a graphic intensive website (Comden & Burgsthaler, 2002).

Audio, Video & Animation
• Provide text alternatives or transcriptions in multiple languages (Lynch & Horton, 2002) for any video, audio and animation used in the site. For video and animations, the alternatives can be both captions of spoken word (subtitles) and auditory descriptions of relevant actions taking place on the screen (University of Wiscosin-Madison, Accessible Multimedia, Web Accessibility 101 Policy, Standards & Design Techniques). These alternatives should be synchronized with the action taking place on the screen.
• The text transcription alternative for audio should be stored as a HTML file. This should be available as a hyperlink immediately after preceding or following the audio link (University of Wiscosin-Madison, Accessible Multimedia, Web Accessibility 101 Policy, Standards & Design Techniques).
• Use video, audio or animations if there is a need for. Optimize these to smaller file size for easy deliverance over the low bandwidth. Do not overuse them.
• Deliver these through an embedded player in the browser as users may not have the appropriate programs installed in their machines to play these files.
• Provide text alternative or HTML version of the website if it’s a animation intensive website.

Applets, Plug-ins & PDF Files
• Provide text alternatives for JavaScripts or plug-ins for any critical function in the site (Corcoran & Corcoran, 2002).
• The website’s application should be designed to work using the standard plug-in so that users don’t have to download and install an additional/new plug-in. If it requires additional/new plug-ins then it should provide links as to where a user can download and install that particular plug-in.
• When using JavaScript make sure to employ the built in accessibility features that are within the Java Developer’s Kit (Comden & Burgsthaler, 2002).
• JavaScripts and plug-ins should work in a device-independent manner (May, 2005).
• When using PDF files display its size so that the users will know how long it will take to download. A link to PDF converters should be made so that users will be able to view the file on their PC. A HTML version of the PDF files should be made available for printing purposes and to cater for users with no PDF converters or who doesn’t wants to (or take time) to download.

Tables & Frames
• Provide row and column headers for data tables.
• Do not use tables for layout unless necessary and if used it should be linearized properly (W3C Web Accessibility Guidelines).
• Provide summaries for tables to briefly explain their purpose (May, 2005).
• Provide table headers.
• Use relative sizing for tables .i.e use percent than pixels for measurements (The Ohio State University Web Accessibility Center).
• Avoid the use of nested tables - tables inside a table.
• Use frames sparingly. And when frames are used it should be supported with alternative text (Comden & Burgsthaler, 2002).
• Use frame titles to facilitate identification and navigation.

• Use the Metadata standards for describing the web pages such as IMS and Dublin Core standards.

• Use emerging language specifications such as XHTML & XML for websites as it makes automatic conversions of content for alternative display easier (Web Accessibility Initiative).
• Structure documents with markups.

Cascading Style Sheets (CSS)
• Use CSS to separate structure from presentation.
• CSS can be used to easily create different presentation for different devices (Web Accessibility Initiative) .
• CSS reduces file size for the web pages, increases the download speed and improves server performances.
• CSS ensures visual continuity for users as they navigate the site (Neilsen, 2000).

Testing & Validation
• The site should be tested on different browsers (including text browser) and on different platforms. The site should also be tested using different screen resolutions.
• Accessibility and Usability evaluation tools should be used to test the validity of the HTML (or XHTML) and the general website maintenance checks.
• Test the validity of the CSS (if any).

The web offers so many opportunities to people with disabilities that are unavailable through any other medium. It offers independence and freedom. However, if the web is not accessible, it excludes a segment of the population that stands to gain the most from the internet. As organizations and designers become aware of and implement accessibility, they will ensure that their content can be accessed by a broader population. Web accessibility is all about following design standards – it’s not just about access to web by the disabled users – it’s about everyone being able to access the web (Moss, 2004)


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Appendix 1: Resource Sites & Tools

Bobby Online
This free service will allows testing of web pages and help expose and repair barriers to accessibility and encourage compliance with existing accessibility guidelines, such as Section 508 and the W3C's Wed Content Accessibility Guidelines

Website Optimization
Free Website Performance Tool and Web Page Speed Analysis

Cynthia Says
The Cynthia Says is a web content accessibility validation solution, it is designed to identify errors in the web content related to Section 508 standards and/or the WCAG guidelines.

Web Accessibility Versatile Evaluator (WAVE)
WAVE is website accessibility verifier and is very informative in relation to accessibility alerts according to W3C guidelines.

A-Prompt is a free accessibility verifier (produced by University of Toronto)

HTML and CSS Validators

W3C Web Accessibility Initiative (WAI)
The Web Accessibility Initiative (WAI) works with organizations around the world to develop strategies, guidelines, and resources to help make the Web accessible to people with disabilities.

W3C's Web Accessibility Initiative’s Web Content Accessibility Guidelines 1.0
These guidelines explain how to make Web content accessible to people with disabilities

Illinois HTML/XHTML Accessibility Best Practices

Americans with Disabilities Act Section 508 Guidelines and Section 508

Appendix 2: Assistive Technologies & Devices

Assistive technology is any item, piece of equipment, or product system that is used to increase, maintain, or improve the functional capabilities of individuals with disabilities. Individuals use assistive technology to accommodate limitations due to their disabilities. These technologies greatly assist access to Web content for people with disabilities.

Examples include:
• Browsers specifically designed for people with disabilities such as BrailleSurf, BrookesTalk, EIAD.
• Voice Browsers such as CoversaWeb, webHearit and TelWeb
• Screen Readers are programs that read out using synthesized speech of what is being displayed on the monitor. Used by people who are visually impaired or have reading and learning difficulties. Eg: JAWS for Windows, ASAW, HAL and OutSpoken etc.
• Speech/Voice Recognition Software are useful for those who have difficulty using mouse or keyboard such as Talk It Type It, Speech Recognition with Windows XP and Dragon NaturallySpeaking.
• Screen Magnification programs which enlarges what is displayed on the computer screen such as VisAbilitiy, SuperNova and JAWS.
• Translation software that allows the reading of the website in foreign languages such as Mastor, BabelFish and MyPersonal Translator.
• Other assistive technologies such as Braille Embossers, Keyboard Filters, Light Signaler Alerts, On-Screen Keyboards and Refreshable Braille Displays.


Philip said...


That's some bit of research you've done there and if you don't mind I think I'll pilfer a bit here and there for one of my assignments.

On another note, how about posting it on the
wiki page. It would make a great page which you/ people could add to.


Jackline said...

Hi Nice Blog .I think HR understands the importance of other people tracking time--IT, Lawyers, non-exempt employees, but struggles with the idea of web time clock .