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(X)HTML Standards and Accessibility: An Introduction Steven C. Perkins, J.D., M.L.L

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An Introduction Steven C. Perkins, J.D., M.L.L. (X)HTML Standards and Accessibility:. 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. - PowerPoint PPT Presentation

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Page 1: (X)HTML Standards and Accessibility:

(X)HTML Standards and Accessibility:

An Introduction

Steven C. Perkins, J.D., M.L.L

Page 2: (X)HTML Standards and Accessibility:

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.

Page 3: (X)HTML Standards and Accessibility:

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.

Page 4: (X)HTML Standards and Accessibility:

The World Wide Web Consortium

• http://www.w3.org/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.

Page 5: (X)HTML Standards and Accessibility:

The W3C Code Standards

• HTML 4.01-Transitional; Strict; Frameset

• XHTML 1.0-Transitional; Strict; Frameset

• XHTML 1.1-Transitional; Strict; Frameset

• CSS Level 1

• CSS Level 2

Page 6: (X)HTML Standards and Accessibility:

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.

• http://validator.w3.org/ and http://jigsaw.w3.org/css-validator/

Page 7: (X)HTML Standards and Accessibility:

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

Page 8: (X)HTML Standards and Accessibility:

Proper (X)HTML Code Structure

• A proper (X)HTML code structure:– <Doctype Declaration>– <html>– <head>– <title></title>– <meta>(if used) (character encoding can go here)– <style></style>(if used)– </head>– <body></body>– </html>

Page 9: (X)HTML Standards and Accessibility:

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.

Page 10: (X)HTML Standards and Accessibility:

How to Test

• Open your web browser and go to http://validator.w3.org/ 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.

Page 11: (X)HTML Standards and Accessibility:

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.

Page 12: (X)HTML Standards and Accessibility:

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.

Page 13: (X)HTML Standards and Accessibility:

Testing CSS

• CSS can be specified in three locations: as a separate page called from the (X)HTML page; as a <style></style> 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.

Page 14: (X)HTML Standards and Accessibility:

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.

Page 15: (X)HTML Standards and Accessibility:

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.

Page 16: (X)HTML Standards and Accessibility:

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.

Page 17: (X)HTML Standards and Accessibility:

(X)HTML and CSS Resources:

• The W3 specifications at http://www.w3.org/

• USENET newsgroups:

• alt.html, alt.html.critique, alt.html.tags and comp.infosystems.www.authoring.html comp.infosystems.www.authoring.stylesheets

Page 18: (X)HTML Standards and Accessibility:

Books:

• Elizabeth Castro, HTML for the World Wide Web: with XHTML and CSS, 5th ed.,Peachpit Press, ISBN:0-321-13007-3

• Eric Meyer, Eric Meyer on CSS, New Riders, ISBN:073571245X

• Many other titles are available.

Page 19: (X)HTML Standards and Accessibility:

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

Page 20: (X)HTML Standards and Accessibility:

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, http://www.webaim.org/info/factsheet.htm

Page 21: (X)HTML Standards and Accessibility:

W3C Web Accessibility Initiative

• WAI home page: http://www.w3.org/WAI/

• Started in 1997

• Develops tools for constructing and testing accessible web pages.

• Develops Web Content Accessibility Guidelines, Checklists, and Techniques

• http://www.w3.org/WAI/Resources/#gl

Page 22: (X)HTML Standards and Accessibility:

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• http://www.w3.org/WAI/Resources/#gl

Page 23: (X)HTML Standards and Accessibility:

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.

Page 24: (X)HTML Standards and Accessibility:

Other Accessibility Initiatives

• Australia, Disability Discrimination Act of 1992.• 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.

Page 25: (X)HTML Standards and Accessibility:

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.

Page 26: (X)HTML Standards and Accessibility:

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.

Page 27: (X)HTML Standards and Accessibility:

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.

• http://www.section508.gov/

Page 28: (X)HTML Standards and Accessibility:

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, http://www.ittatc.org/laws/stateLawAtGlance.cfm

Page 29: (X)HTML Standards and Accessibility:

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.

Page 30: (X)HTML Standards and Accessibility:

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.

Page 31: (X)HTML Standards and Accessibility:

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.

Page 32: (X)HTML Standards and Accessibility:

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.

Page 33: (X)HTML Standards and Accessibility:

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.

Page 34: (X)HTML Standards and Accessibility:

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.

Page 35: (X)HTML Standards and Accessibility:

Checking Accessibility

• Checking for compliance involves using testing tools and subjective interpretation.

• Bobby, http://bobby.watchfire.com/bobby/html/en/

• Cynthia Says, http://www.cynthiasays.com/

• Wave 3.0, http://www.wave.webaim.org/index.jsp

Page 36: (X)HTML Standards and Accessibility:

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.

Page 37: (X)HTML Standards and Accessibility:

Testing (cont.)

• Use JAWS, IBM Home Page Reader, EMACSpeak, etc., to use the page.

• Have disabled users test the page.

Page 38: (X)HTML Standards and Accessibility:

Resources

• For (X)HTML coding:

• http://www.w3.org/

• For CSS in addition to the above:

• css-discuss [[email protected]]

• http://www.css-discuss.org/mailman/listinfo/css-d

• evolt.org-- http://www.evolt.org/

Page 39: (X)HTML Standards and Accessibility:

Accessibility Resources

• WAI at http://www.w3.org/WAI/

• Section508: The Road to Accessibility:http://www.section508.gov/

• The webaim-forum at http://www.webaim.org/

• ITTATC at http://www.ittatc.org/laws/stateLawAtGlance.cfm

• Connecticut Website Accessibility Committee:

• http://www.cmac.state.ct.us/access/Default.htm

Page 40: (X)HTML Standards and Accessibility:

Books

• Joe Clark, Building Accessible Websites, New Riders, 2002, ISBN:0-7357-1150-X.

• Jim Thatcher, et.al., Accessible Websites, Glasshaus, 2002, ISBN:1-904151-00-0.

• Jeffrey Zeldman, designing with web standards, New Riders, 2003, ISBN:0-7357-1201-8.

Page 41: (X)HTML Standards and Accessibility:

On-line Tutorial

• I think this is one of the best on-line tutorials on accessibility coding:

• Jennifer Foltz, ADA Compliance Workshop Part 1, http://www.oznet.ksu.edu/agronomy/TECHSPT/tutorials