Presentation on theme: "(X)HTML Standards and Accessibility: An Introduction Steven C. Perkins, J.D., M.L.L."— Presentation transcript:
(X)HTML Standards and Accessibility: An Introduction Steven C. Perkins, J.D., M.L.L
Why Care about Code Standards and Accessibility? As the WWW develops, non-standard web pages will not be fully integrated into the Semantic Web and Web Services. As browsers more fully implement the code standards, pages will not display as intended if they are not coded to the standards. Hundreds of millions of persons throughout the world have physical disabilities that cause them difficulty when using the WWW.
Why Care? (cont.) People differ in their learning and web usage styles. Attention to accessibility broadens the reach of your web pages. Various levels of Accessibility are being required by law.
The World Wide Web Consortium Started in 1994 Headed by Dr. Timothy Berners-Lee Based at MIT and affiliated with CERN, DARPA, INRIA, KEIO and ERCIM. Develops the standards defining the web protocols and languages. Develops tools and applications to implement the standards.
What is Standards Compliance? Follows the W3C requirements for the version of HTML or XHTML used in the page. Follows the W3C requirements for the version of Cascading Style Sheets, CSS 1 or CSS2, used in the page. Passes the tests of the W3C (X)HTML Validator and the W3C CSS Validator. and
Well Formed Pages The following are needed to have a well formed (X)HTML page: A Document Type Definition A character encoding A proper (X)HTML code structure
Proper (X)HTML Code Structure A proper (X)HTML code structure: – – (if used) (character encoding can go here) – (if used) –
Testing for Valid Code The easiest way is to write valid code, either by-hand or using HTML-Tidy, as a stand alone application or as part of HTML-Kit. Most commercial web coding applications do not produce valid code. Several do have extra programs to help with validity.
How to Test Open your web browser and go to You can enter a web address or upload code to the validator. The validator will test your code against the DTD of the Doctype Declaration that starts your code. If either the Doctype Declaration or the Character Encoding are not specified, the validator can not validate the page.
Working with the Validator When you test the page you will either pass or fail. If you pass, you get no information from the test. If you fail, you get a list of errors with an explanation, and the complete source listing for your page. Save the result.
Working with TIDY From the Validator page, you can select Tidy-Online. You use it like the Validator and it reformats your code to meet the XHTML 1.0T DTD. You need to save its result and run it through the Validator. Repeat the process until you have a valid page.
Testing CSS CSS can be specified in three locations: as a separate page called from the (X)HTML page; as a section in the head of the document code; or as an individual style statement on an element. All combinations are acceptable. The best practice is to have a separate style page.
The CSS Validator The CSS Validator can be accessed directly or from the Validator page. It is used in the same way as the code Validator: type in a page address or uplaod a page with CSS. You will get the same type of result as from code Validator. Save the result and use Tidy to correct it. Once both (X)HTML code and CSS pass the validation tests you are ready to look at Accessibility issues.
Issues to Consider Use of the Document Type Declaration causes different responses in each browser. There is a page that details which Doctype Declarations put browsers into Standards compliance, almost standards compliance and not in compliance modes. What browsers are used by visitors to your site may control whether you use transitional or strict Doctypes and whether you need to support 4.X series browsers.
Issues (cont.) Use of tables for layout is allowed by W3 standards. You must not use the markup for Data Tables in Layout Tables. Be sure the page content linearizes, i.e., that it can be read if viewed in LYNX text mode.
(X)HTML and CSS Resources: The W3 specifications at USENET newsgroups: alt.html, alt.html.critique, alt.html.tags and comp.infosystems.www.authoring.html comp.infosystems.www.authoring.styleshe ets
Books: Elizabeth Castro, HTML for the World Wide Web: with XHTML and CSS, 5 th ed.,Peachpit Press, ISBN: Eric Meyer, Eric Meyer on CSS, New Riders, ISBN: X Many other titles are available.
Facts about Disabilities Blindness and Low Vision affects 15 million people in the USA. –They use “Screen Readers” and keyboard navigation. Motor disabilities, SPI, CP, MS, account for 1.2 to 1.5 million persons in the USA –They use assistive technology and can’t use a mouse for navigation
Facts (cont.) Deafness and loss of hearing, 22 million persons in the USA. –Can’t hear audio only materials or soundtracks to film content. Source: WEBAIM Disability Fact Sheet,
W3C Web Accessibility Initiative WAI home page: Started in 1997 Develops tools for constructing and testing accessible web pages. Develops Web Content Accessibility Guidelines, Checklists, and Techniques
Other WAI Activities Authoring Tool Accessibility Guidelines, Checklists, and Techniques. User Agent Accessibility Guidelines, Checklists, and Techniques. XML Accessibility Guidelines Accessibility features of SMIL, SVG, CSS, and HTML 4. Evaluation and Repair Tools
Other Accessibility Initiatives United Nations, Rule 5 of the Standard Rules on the Equalization of Opportunities for People with Disabilities. European Union, Accessibility of Public Websites, Council Resolution (2001). UK: Disability Discrimination Act of 1995: Parts III and IV; and, the Special Educational Needs and Disability Act of 2001.
Other Accessibility Initiatives Australia, Disability Discrimination Act of New Zealand, New Zealand Government Web Guidelines Version 2.1. Canada, Government of Canada Internet Guide, section on Universal Accessibility. USA: Rehabilitation Act of 1986, Section 504, and Section 508 Standards for Electronic and Information Technology (1998); Americans with Disabilities Act (1990) and Telecommunications Act of 1996, Section 255.
Website Accessibility in the USA Prior to the development of graphics intensive computer applications, accessibility to the Internet was enabled by using character based applications with adaptive equipment.
Website Accessibility in the USA The rise of the WWW and the development of variant HTML dialects by commercial enterprises, combined with the move to graphical applications, caused a breakdown in the accessibility of the Internet. The City of San Jose court case, brought under the ADA, caused a change in the regulatory climate in the USA and brought website accessibility to the attention of a larger audience. DOJ rules that ADA accessibility requirements apply to web pages, 9 Sept 1996.
Website Accessibility in the USA With the enactment of the Rehabilitation Act Amendments of 1998, Section 508 became the principal law regarding government websites and websites of those doing substantial business with the government. Based of WACG 1.0 Priority Level 1 with some additional requirements.
US States and Accessibility A list of all state laws, standards and regulations regarding website accessibility is at the website of the Information Technology Technical Assistance and Training Center, e.cfm e.cfm
State Requirements States have based their requirements on the WAI WCAG, on ADA, and on Section 508. Some states apply the standards to all entities financed in full or part with public funds. Educational websites were specifically included in the UK’s SENDA regulations.
Issues to Consider Colors should be used that will not confuse colorblind users. Tabindex and Accesskey coding should be used to accommodate those who can not use a mouse. Skip navigation links should be provided so those using screen readers do not have to go through long lists of links to get to an item of interest.
Issues (cont.) Alt text should be used for all informative images. Null alt tags are used for spacer gifs and the like. Frames, image maps, and applets should be avoided. The title attribute should be used with the above to enhance use. Fieldset, summary, and labels should be used with forms.
More Issues Layout tables do not have labels. Data tables use headers and summary to allow linearized reading. Axis and id are used with complex data tables. Use CSS to control the order of display and place navigation lists at the bottom of the code page. Provide text or RTF versions of PDF files.
More Issues (cont.) Provide transcripts of audio materials and captioning for video materials. Allow the user to control the size of text by using relative sizes or providing a style switcher. Provide an explanation of the accessibility features of the website.
Accessibility Compliance Depends on the country and the standard adopted. WAI WCAG Level I, II, or III. USA Section 508 is a combination of WCAG Level I and additional requirements.
Checking Accessibility Checking for compliance involves using testing tools and subjective interpretation. Bobby, Cynthia Says, Wave 3.0,
Testing Accessibility Use the standard accessibility applications for your platform to test for compliance. Use LYNX to view the page and determine if it is useable. Turn off colors and view the screen in black and white. Turn off sound and see if you can still navigate and understand the page.
Testing (cont.) Use JAWS, IBM Home Page Reader, EMACSpeak, etc., to use the page. Have disabled users test the page.
Resources For (X)HTML coding: For CSS in addition to the above: css-discuss discuss.org/mailman/listinfo/css-dhttp://www.css- discuss.org/mailman/listinfo/css-d evolt.org--
Accessibility Resources WAI at Section508: The Road to Accessibility: The webaim-forum at ITTATC at Connecticut Website Accessibility Committee:
Books Joe Clark, Building Accessible Websites, New Riders, 2002, ISBN: X. Jim Thatcher, et.al., Accessible Websites, Glasshaus, 2002, ISBN: Jeffrey Zeldman, designing with web standards, New Riders, 2003, ISBN:
On-line Tutorial I think this is one of the best on-line tutorials on accessibility coding: Jennifer Foltz, ADA Compliance Workshop Part 1, SPT/tutorials SPT/tutorials