Websites and Tools
Accessibility Evaluation Tools
- WAVE is a free web accessibility evaluation tool provided by WebAIM. It is used to aid humans in the web accessibility evaluation process. Rather than providing a complex technical report, WAVE shows the original web page with embedded icons and indicators that reveal the accessibility information within your page.
- Color Contrast Analyser for Web Pages (for the PC)
A tool for checking foreground & background colour combinations to determine if they provide good color visibility. Determining "color visibility" is based on algorithms suggested by the World Wide Web Consortium.
- Colour Contrast Check Tool (Web Based)
This tool allows you to specify a foreground and a background color and determine if they provide enough of a contrast "when viewed by someone having color deficits or when viewed on a black and white screen."
- Sim Daltonism (color blindness simulator for Mac OS X)
A color blindness simulator that filters in real-time the area around the mouse pointer and displays the result — as seen by a color blind person — in a floating palette.
- Lighthouse International
Examples of different color combinations and how they affect people with partial sight and color deficiencies.
CSS, Markup and Web Standards
- Visit A List Apart to learn about web standards. A List Apart Magazine (ISSN: 1534-0295) explores the design, development, and meaning of web content, with a special focus on web standards and best practices.
- Online since May 1995, Jeffrey Zeldman Presents is the personal site of designer, writer, and stunt double Jeffrey Zeldman. Jeffrey Zeldman’s Daily Report is one of the oldest continuously published blogs and a registered periodical: ISSN No. 1534-0309.
- Meyerweb.com is the place to go for a collection of cutting-edge CSS-driven design demos, as a way of showing just how far you can take CSS in a browser that fully supports it.
- SimpleBits designs and builds simple, usable, and attractive interfaces that account for speed, file size, readability and accessibility — using web standards and is a great to find tips and get inspired.
- W3C CSS Validation Service to validate Style Sheets.
- Markup Validation Service to validate XHTML.
- Doctype 101 at A List Apart.
- Download an example of an accessible bar graph that was made with tables and styles. Created by Eric Meyer, the CSS Jedi.
- "Introduction to the Screen Reader" with Neal Ewers of the Trace Research Center is a short 6 minute video demonstrating how screen readers assist people who are blind navigate the web, access the electronic page, and more.
- JAWS Keystrokes by Freedom Scientific.
Web Accessibility Basics
- Learn more about the essential components of accessibility that include content, natural information, markup, user agents, assistive technology, user knowledge, authoring tools and evaluation tools.
- The WCAG 2.0 guidelines explain how to make Web content accessible to people with disabilities. The guidelines are intended for all Web content developers (page authors and site designers) and for developers of authoring tools.
- How People with Disabilities Use the Web, illustrates some of their requirements when using Web sites and Web-based applications, and provides supporting information for the guidelines and technical work of the World Wide Web Consortium's (W3C) Web Accessibility Initiative (WAI).
Types of Disabilities
Web users experience many different disabilities and combinations of disabilities.
- Visual Disabilities: blindness, low vision, color blindness
- Hearing Impairments: deafness, hard of hearing
- Physical Disabilities: motor disabilities
- Speech Disabilities
- Cognitive and Neurological Disabilities: dyslexia and dyscalculia, ADD, intellectual disabilities, memory impairments, mental health disabilities, seizure disorders.
- Multiple Disabilities
- Aging Related Conditions
Form more in depth information on types of disabilities visit:
Interacting with People with Disabilities
Many people feel uncomfortable around people with disabilities. Some people feel sorry for people with disabilities, and assume they are bitter about their disabilities, which is untrue in many cases. Many people feel their lives are enriched by their experiences with disability.
Don’t worry about “saying the wrong thing” around people with disabilities. That’s not a big deal to most people with disabilities. What’s important is that you respect the person and see them beyond their disability.
- Don’t make assumptions about people or their disabilities about what they want, feel or what is best for them.
- Ask before you help. People with disabilities may appear to be struggling, but would prefer to complete a task.
- Talk directly to the person, not to the interpreter, attendant, or friend. Sit down so that you are eye level with a person in a wheel chair.
- Speak normally. Don’t speak louder and slower to people with disabilities. Use normal language including “see” and “look”, even for blind people.
- Use “people-first” language. For example, say “a man who is blind” rather than “a blind man, and “a woman who uses a wheelchair” instead of “a wheelchair-bound woman”.
- Avoid potentially offensive terms or euphemisms. Commonly accepted terminology includes “people with disabilities” and “a person with a visual/hearing/physical/speech/cognitive impairment”. Many people find annoying or offensive: restricted to wheelchair, victim of, suffers from, retarded, deformed, crippled, and euphemisms such as physically challenged. If you are unsure ask the person with a disability what terminology he prefers.
- Be aware of personal space. Don’t touch, move, lean on mobility aids like a wheelchair, walker, or cane.
- Americans with Disabilities Act (ADA)
- The A.D.A. is a U.S. law passed in 1990 that prohibits discrimination against people with disabilities.
- Authoring Tools Accessibility Guidelines (ATAG)
- ATAG were published by the W3C in 2000 to assist authoring tool developers in "designing authoring tools that produce accessible Web content and to assist developers in creating an accessible authoring interface." In other words, your blogging tool or CMS should not only produce accessible pages, but also be accessible itself so that users with disabilities can create content.
- Section 255 of the Telecommunications Act of 1996
- Section 255 requires that manufacturers of telecommunications services, make their products and services accessible to, and usable by, persons with disabilities, unless it is not "readily achievable" to do so.
This is not a federal procurement law, and it has lower burden for compliance than Section 508, because "readily achievable" means without significant difficulty or expense. It also has one major limitation, in that Section 255 does not cover every function of service in the scope of the telephone network.
- Section 508
- A common name for Section 508 of the Rehabilitation Act. This is an amendment to a U.S. law that basically says all electronic and information technology purchased or developed by the U.S. government must be accessible to people with disabilities.
- User Agent Accessibility Guidelines (UAAG)
- UAAG provides guidelines for designing accessible user agents (browsers, assistive technologies, media players, and the like), published by the W3C in 2002. User agents include HTML browsers and other types of software that retrieve and render Web content. A user agent that conforms to these guidelines will promote accessibility through its own user interface and through other internal facilities, including its ability to communicate with other technologies (especially assistive technologies). Furthermore, all users, not just users with disabilities, should find conforming user agents to be more usable.
- Web Accessibility Initiative (WAI)
- The Web Accessibility Initiative was started by the W3C and its members, an organization that addresses web accessibility issues.
- Web Accessibility Tools Consortium (WAT-C)
- Described as a consortium that "provides a collection of free tools to assist both developers and designers in the development and testing of accessible web content." The consortium is a collaboration of some of the world's leading accessibility practitioners, founded by Accessible Information Solutions (Australia), Infoaxia (Japan), The Paciello Group (USA), Wrong HTML (Japan), and Juicy Studio (UK).
- Web Content Accessibility Guidelines (WCAG)
- WCAG 2.0 were developed by the W3C/WAI to address issues in building accessible web pages.
- Web Standards Project (WaSP)
- WaSP is described as a project that "was formed in 1998 with the goal of promoting core web standards and encouraging browser makers to do the same, thereby ensuring simple, affordable access for all."
- World Wide Web Consortium (W3C)
- An international consortium of companies and organizations involved with the Internet and the World Wide Web, responsible for maintaining web technology standards, such as HTML and CSS.
JAWS for Windows is a powerful accessibility solution that reads information on your screen using synthesized speech. JAWS provides many useful commands that make it easier to use programs, edit documents, and read Web pages. With a refreshable braille display, JAWS can also provide braille output in addition to, or instead of, speech.
Freedom Scientific provides a free download for JAWS 40 minute mode. Your computer must be restarted to use JAWS again after the 40 minutes have expired.
Freedom Scientific also provides a list of JAWS keystrokes.
Window-Eyes is available for Windows 2000, Windows XP (Home, Professional, and Media Center), Windows Server 2003, and Windows Vista (all 32-bit versions, including Vista Ultimate, Vista Home Premium, Vista Home Basic, Vista Business, and Vista Enterprise).
Window-Eyes gives total control over what you hear and how you hear it. Plus, with its enhanced Braille support that control is extended to what you feel as well. Most applications work right out of the box with no need for endless tinkering in order to get them to function properly.
GW Mirco provides a free download of a 30 minute demo. You will need to reboot for an additional 30 minutes.
VoiceOver, (Apple operating system 10.4 and later) is intended to provide those who are blind, have low vision, or learning difficulties the ability to use a Macintosh. It’s perfect for those who have never used a computer or screen reader before. With VoiceOver, you can create and edit word processing documents, send e-mail and browse the World Wide Web and even play chess.
Speech Recognition Software
With Dragon NaturallySpeaking you can talk to your computer and watch words quickly appear in documents, e-mails, instant messages and even surf the web simply by speaking.
Refreshable Braille Displays
An assistive device that turns information into raised Braille characters electromechanically, by raising small pins up through holes in a plate, which can be sensed by users placing their fingers on the plate.
See examples of Refreshable Braille Displays.
- Accessibility Task Force (ATF)
- A subgroup of the WEB Standards Project (WaSP) focusing on accessibility, assistive technology, and standards support.
- A generic term describing descriptive text attached to certain object on a web page that can be read aloud by a screen reader, so that a person with visual impairment can know the nature of such objects, too. Alt-text is therefore an accessible alternative to a potentially inaccessible item of content. For example, the object element may use the text embedded within it as a fallback mechanism.
The most common alternative text is found as an attribute of the
img element, and it describes the function of an image, or is blank in the case of purely decorative images.
- A Java program or application that provides interactivity not offered by (X)HTML and designed to be embedded in, and invoked from, a web page. In many cases, Flash has superseded applets as the means to achieve extra interactivity.
- assistive technology
- Equipment or software that assists people with disabilities in performing everyday activities. Examples include screen readers and voice-input software.
- In WCAG 2.0, a set of technologies assumed to be supported by, and enabled in, user agents in order for web content to conform to WCAG 2.0. Some examples of entities that may set baselines include authors, companies, customers, and government entities.
- A free Web site accessibility assessment tool developed by CAST (www.cast.org/). and then acquired by Wathfire (www.watchfire.com/). The free version of Bobby was discontinued in April 2003.
Bobby had some utility in checking for things like missing alt-text, but, unfortunately, it lulled site owners into a false sense of security, as they believed that "passing Bobby" guaranteed accessibility. There are many other online "validators," such as Cynthia Says and the WAVE. Gez Lemon has a salutary article about the usefulness of such programs at juicystudio.com/article/invalid-content-accessibility-validators.php.
- The software on a computer that allows Web sites to be rendered so they can be displayed to users. There are two types of visual browsers. Internet Explorer, Firefox, Opera, Safari, and the like render all content including the latest technologies. Others, like Lynx, are text only. But many other types of browsers exist, some of which produce voice output, such as IBM Home Page Reader.
- Cascading Style Sheets (CSS)
- A means of applying styling/formatting to markup (for example, XML or HTML). This has many advantages over using HTML formatting tags, such as
font. For a start, CSS formatting is more powerful and allows more flexibility. If you want to change a style you need only change its definition in the style sheet, rather than changing every instance of it in the HTML. CSS has great uses for accessibility. For example, you can use an alternative style sheet to make the text on a Web site bigger for the benefit of people with visual impairments.
- content management system (CMS)
- A program that allows users to create and manage web pages and other content. CMSs are often browser-based. They can range from free blogging tools, such as WordPress, to expensive systems that can run a whole enterprise site, such as TeamSite or Vignette. They are generally template-driven and promise (with varying success) to turn user's text-based input into HTML. Many spit out horribly inaccessible code, and most do not conform to ATAG and are therefore unable to be used by people with disabilities to produce sites. It's always important to ask vendors about their conformance to ATAG before purchasing a CMS.
- Disability Discrimination Act (DDA)
- A name shared by two laws passed in Australia (1992) and the United Kingdom (1995, extended 2005). They both prohibit discrimination against people with disabilities.
- Document Object Model (DOM)
- Document Type Definition (DTD)
- A file that defines the relationships and constraints for elements and attributes used in the markup language in the form of a schema. For example, a DTD may define whether an attribute is required for a particular element. Effectively, it's the grammatical rules for the language.
- A language-based learning disability that is often characterized by difficulties with understanding written language and being more attuned to a graphical or an object-based learning style.
- Extensible Hypertext Markup Language (XHTML)
- Defined by the W3C as "a reformulation of the three HTML 4 document types as applications of XML 1.0. It is intended to be used as a language for content that is both XML-conforming and, if some simple guidelines are followed, operates in HTML 4 conforming user agent" (www.w3.org/TR/xhtml1/#xhtml).
XHTML is very much like HTML with a few extra rules. There are three main flavors. XHTML 1.0 Transitional allows many deprecated tags, and as the name suggests, was designed to help developers make the transition from HTML. XHTML 1.0 Frameset allows frames and therefore has attendant accessibility issues. XHTML 1.0 Strict is, well, strict (when compared with traditional HTML).
The idea that XHTML is "better" than HTML is subject to ferocious (but rather futile) debate, as it is largely a matter of personal preference, understanding the difference, and using the right tools for the job.
- Extensible Markup Language (XML)
- A language specification from the W3C that allows users to develop their own markup languages (often called vocabularies), and format there documents using style sheets to be presented on a browser if desired. XML has a very strict set of rules that must be adhered to, allowing a lot of control over document format. XML is most useful, however, as a completely language/platform-agnostic data format.
- Extensible Stylesheet Language (XSL)
- A W3C specification that contains three parts; Extensible Stylesheet Language Transformations (XSLT) for changing the formatting structure of markup according to a set of rules, Extensible Stylesheet Language Formatting Objects (XSL-FO) for applying a strong set of rules to a document to ensure reliable formatting when printed, and XPath to select the elements required by XSLT.
- An open source browser available for all main operating systems, developed by the Mozilla Corporation. The good (but no perfect) standards support and availability of community-written extensions makes it the browser of choice for many web developers.
- The name given to the product by Adobe (formerly Macromedia) that allows moving graphics to be displayed in a web page. If refers to the Flash Player, which plugs in to the browser, a well as (more generally) the program and effects. Flash can be made accessible on Windows machines via MSAA, and some of the most widespread screen readers can access the content. Although Flash has gotten bad press from some accessibility advocates, it has proved very helpful in delivering accessible content to people with cognitive disabilities.
- A product from Adobe (formerly Macromedia) that allows a developer to create a rich interactive web page that can update with the server in real time, with Ajax-like results.
- A feature of (X)HTML that allows a web author to divide a page into two or more separate windows. If the frame does not have
title element, or the
title element is not meaningful, this can cause accessibility issues. In addition, some browsers do not support frames.
- Hypertext Markup Language (HTML)
- The markup language that is used to create the vast majority of web pages. The standards for HTML are controlled by the W3C.
- image map
- An area of an image on a web page that has links to other areas of the Web. for example, an image map could take the form of a map of Europe, in which clicking the map of England could open a page about warm beer, rain, and world-renowned cuisine; where as the are corresponding to Belgium takes you to a page about great beer and a list of household names from all fields of human endeavor.
There are two types of image maps: client-side and server-side. If you want to use an image map, make it a client-side image map. A List Apart has a good article on building an accessible, standards-compliant image map.
- An object-oriented programming language developed by Sun Microsystmes. java was specifically designed for the distributed environment of the Web and can be used to create applications that can run a on single computer or distributed among several computers in a network. It can also be used to write applets (small, stand-alone programs) or animations, although Flash is more commonly used for these.
- A scripting language often used on web pages. It's a type of ECMAScript.
- The process of removing the cellular structure from a layout table and checking the cells' contents in their linear (source) order, left to right, top to bottom. Linearization takes the contents of row 1 column 1, then row 1 column 2, and so on. If any cells contain a nested table, all of those cells are linearized before proceeding to the next cell of the original table. The Lynx browser or Web Developer plug-in for Firefox is a good way to see the linearized structure.
The purpose of linearization is to see if the content still makes sense, as the linearized order is the order in which a screen reader will voice the web page to the user. If it does still make sense (and it generally does), both WCAG 1.0 and 2.0 say your layout is accessible. But no one has professionally used tables to lay out web pages since Mozart fell off his penny-farthing during a stegosaurus hunt.
- A text-only browser that was popular among UNIX users and sometimes used by people with disabilities and those in low-bandwidth areas. Download the Lynx browser. A Lynx emulator is also available and is useful for testing how tables linearize.
- Microsoft Active Accessibility (MSAA)
- A layer in all modern Windows systems that allows assistive technologies to hook into applications. It is how screen readers "know" what is on screen.
- Using a computer to present multiple types of media simultaneously, in an integrated manner. Media can include sound, graphics, video, text, animation, or any other form of information representation. For the purposes of WCAG 2.0, multimedia refers to combined audio and video presentations, as well as audio-only and video-only presentations that include interaction.
- on-screen keyboard
- A keyboard that appears on the screen. Users who cannot use their hands can use assitive technology (such as a head pointer) to enter keyboard input via the on-screen keyboard.
- In WCAG 2.0, refers to the determination of the application of process. What were the results of the application of a specific guideline? Were the success criteria achieved?
- PAS 78
- The Publicly Available Specification from the British Standards Institution (BSI), titled "Guide to Good Practice in Commissioning Accessible Web sites," released in March 2006.
- A module (either hardware or software) that adds a special feature to a larger system or program; for example, a program to play movies on a browser or plug-in that allows browsers to display Flash content.
- Portable Document Format (PDF)
- Developed by Adobe systems Inc. as a way to publish documents electronically, with good formatting for printing and document security (documents are generally read-only). Originally, it was an image format, and this presented major accessibility issues. Recently however, Adobe has made large strides in making the PDF format accessible to people with disabilities, although it's generally more complex to navigate a PDF file or to make a PDF file accessible than doing so with an equivalent HTML document.
- programmatically determined
- refreshable Braille display
- An assitive device that turns information into raised Braille characters electromechanically, by raising small pins up through holes in a plate, which can be sensed by users placing their fingers on the plate.
- Scalable Vector Graphics (SVG)
- A language for vector graphics coded in XML. XML documents can have these graphics placed directly into the document, with many advantages. SVG produces graphics that are smaller, transmit more quickly, are scalable without loss of resolution, can have searchable text labels, and can be interactive. SVG is being developed by W3C.
- In WCAG 2.0, refers to limiting conformance claims to pertain to only some parts of a Web site. Scoping allows authors to claim conformance to WCAG2.0 for all URLs in one part of a site and exclude other parts of the site. "Scoping cannot exlude a particular type of content (for example, images or scripts) since it would allow exclusion of individual success criteria."
- screen magnifier
- A device (or software) that will make images and text on a screen larger for the benefit of visually impaired users. Many Microsoft Windows machines have a simple screen magnifier built in (available from the Start » Programs » Accessories » Accessibility menu).
- screen reader
- A computer program that reads the screen to a user. It can be used to surf the Web, to write a spreadsheet or document, or just to read pages. It is closely related to voice output. In many ways, screen reader is a misnomer; most modern screen readers actually read the text in source-code order, regardless of the positions of the various elements in the visual layout. Examples of screen readers are JAWS for Windows, Window-Eyes, and VoiceOver on Mac OS X version 10.4.
- spacer image
- Small, transparent image placed on a page, usually in a table-based layout, also called spacer GIF. Spacer images are an old-fashioned way to position text and images on the page for a good visual effect. These should be found only in legacy pages, and should have null alt-text (
- style guide
- A document that sets out the rules for your Web site. All your developers must follow your style guide. Accessibility rules and standards can be included in this style guide. This is a good idea, as when a style guide is implemented, accessibility becomes part of the basic parameters for your Web site and becomes much less of an issue.
- success criteria
- In WCAG 2.0, testable statements that will be either true or flase when applied to specific web content (see www.w3.org/TR/UNDERSTANDING-WCAG20/).
- Synchronized Accessible Media Interchange (SAMI)
- An HTML-like language used to embed captions in Windows Media files.
- Synchronized Multimedia Integration Language (SMIL)
- A markup language developed by the W3C that allows developers to separate multimedia content into distinct files and transmission streams such as text, images, audio, and video. These can then be sent to the user's computer separately, reassembled, and displayed as intended. SMIL 2.1 became a recommendation in December 2005.
- text equivalent
- A term used to describe the technique of providing a text alternative that will be the same in both content and function as a nontext object on a web page, such as an image map.
- text-only browser
- A browser that does not show images. It does not have images turned off; rather, it just doesn't display them. An example of a text-only browser is Lynx.
- universal access
- The idea that all things on the Internet should be accessible by the largest audience possible, regardless of disability, location, device, or speed of connection to the Internet. It therefore differs from accessibility, which is solely concerned with access for people with disabilities.
- universal design
- Designing for the largest audience possible, regardless of disability or ability to speak the native language. This is a process rather than an end in itself.
- The idea that a Web site or web page is easily used by a web user.
- user agent
- A term used by the W3C as a generic description for "any software that retrieves and renders Web content for users." A browser, mobile phone, screen reader, plug-in, or search engine's web crawler may be considered a user agent.
- user-centered design (UCD)
- The design process that places the user at the center of the design rather than the object to be designed. It is a philosophy and process rather than an end in itself.
- voice input
- Software that recognizes voice commands and responds accordingly.
- voice output
- Software that reads the necessary information to the user, in a synthesized voice.
- voice recognition software
- Software that can be trained to recognize a person's voice and either execute commands or turn the voice into text or other forms of media, such as sign language for the deaf.
- A type of XML that allows the user to interact with a web page using voice recognition software.
- voicing browser
- A browser that uses synthesized voice as a means to communicate with the user. IBM Home Page Reader is an example. It differs from a screen reader in that a voicing browser is purely a web browser, whereas a screen reader reads any screen.
- Chisholm, W, ed, Vanderheiden, G, ed, Jacobs, I, ed, Web Content Accessibility Guidelines 1.0. World Wide Web Consortium. May 1999.
- Mills, C, ed, Web Accessibility: Web Standards and Regulatory Compliance. Berkeley, CA: friends of ED/Apress, 2006.