Web Content Accessibility Guidelines

Logo for conformity with WCAG 2.0 at level AAA

The Web Content Accessibility Guidelines ( WCAG ; English for "guidelines for barrier-free web content") are an international standard for the barrier-free design of Internet offerings , which will apply in the European Union for public bodies from 23 September 2019 for new and from 23 September 2020 for existing ones Websites and from June 23, 2021 for mobile applications with WCAG 2.1 level AA is binding. The Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C) developed the WCAG, the International Organization for Standardization (ISO) declared WCAG 2.0 to be the ISO / IEC 40500: 2012 standard, and the European Committee for Standardization (CEN ), the European Committee for Electrotechnical Standardization (CENELEC) and the European Telecommunications Standards Institute (ETSI) have declared WCAG 2.1 to be the standard EN 301 549 V2.1.2 (2018-08).

Websites that comply with these guidelines are also accessible to people with sensory and motor (and to some extent mental) impairments; In other words, they can record the information offered and make the necessary entries. The WCAG are at the center of numerous guidelines and specifications that the WAI has developed to promote an accessible Internet. In Germany, the practical implementation of these guidelines is still in the early stages and has been supported since 2002 by being legally anchored in the Accessible Information Technology Ordinance (BITV).

The old version WCAG 1.0 had recommendation status since May 1999 . The current version WCAG 2.0 was adopted on December 11, 2008 after more than nine years of deliberation, and an authorized German translation is now available. In June 2018, the WAI passed WCAG 2.1.

backgrounds

The WAI develops guidelines for the barrier-free design of the Internet. The activity is not focused solely on the content of the website. There are also recommendations for authoring tools and user agents ( browsers , media players and other assistive technologies ). The activity also includes comprehensive information on the subject of barrier-free Internet.

With the increasing spread of the World Wide Web (WWW) in the 1990s and with it the spread of graphically displayed websites, the problem that the information on the web offers was no longer accessible for people with disabilities became acute. This development, which at first glance appears bizarre - the increasing exclusion of these people while at the same time simplifying operation for others - has several reasons. In the 1980s, the character and line-oriented display of the user interfaces of operating systems such as MS-DOS , Unix , CP / M was easily accessible for deaf, blind or similarly disabled people, because the linear structure of the display in line-oriented terminal programs or the lack of acoustic output is not a barrier to braille displays and other assistive technologies. Disabled and non-disabled people could communicate unhindered. Even graphically oriented representations of the system interfaces do not in themselves represent a barrier for people whose visual abilities are restricted or who cannot operate a mouse. For example, modern versions of the Windows operating system fully support keyboard operation. The main problems lie in the lack of application of the existing standards. The following reasons play a role:

• the high complexity of web design: numerous different technologies make it difficult to create web offers that are generally easily accessible.
• lack of standard conformity of the browser
• lack of problem awareness among web designers
• Operation is not possible regardless of the device used: Control and inputs with mouse, keyboard and other input devices must, however, be possible.

Some examples of problematic web designs:

• Before CSS was widely supported, HTML tables were a preferred means of designing the layout. The two-dimensional structure thus created can not be reproduced appropriately by Braille displays or screen readers , since the presentation often does not reflect the actual context of the data.
• Hyperlinks whose descriptive text does not contain any reference to the destination (e.g. a link with the text “here”) are also difficult to grasp for the visually impaired.

In principle, accessibility does not represent a high additional expense and is only a partial aspect of the comprehensive usability of computer technologies. The prerequisite, however, is that the additional requirements are included in the planning processes from the start, as subsequent changes are often too time-consuming. Accessibility does not mean renouncing good design. Pure HTML pages are generally not barrier-free and multimedia content in particular can promote accessibility for certain types of disability. For example, people who are deaf from birth can often only read poorly because the writing is derived from spoken language, which they cannot or only poorly master. Illustrative images can then promote understanding of the text, which should also be kept simple.

Similar problems also occur in other areas of computer-based work. For example, the work as a programmer for blind people is becoming increasingly difficult, because with the spread of graphically oriented notations of software models in the form of UML etc., the lack of accessibility of the UML diagrams for the blind has the effect of excluding them.

Effects

Although the recommendations of the W3C have no legal validity with regard to the development of the Internet, they are nevertheless highly binding for the development. In general, software conformity with the W3C standards is expected. This primarily affects the browser, which is the most important interface to the Internet. The reason for this lies among other things in the impartial work and the open and discursive development of the standards of the W3C. In addition, the WCAG has already been incorporated into the legislation of individual states. The US government also signaled support for the guidelines very early on. For example, with the BITV, the German federal government has made the guidelines of WCAG 1.0 legally binding for all federal websites. Individual federal states are gradually adopting this for the state level as well. To put it bluntly, this is the first time that a recommendation by the W3C has received legally valid status as a regulation.

Although the valid hypertext standards of the WWW (HTML, XHTML ) offer the possibility to make websites accessible with additional information, they were never used extensively, so that it became clear that separate guidelines for accessibility are necessary. In fact, the WCAG are also successful, even if it is still not possible to speak of general accessibility of the Internet. Numerous international and national initiatives support these recommendations. For example, the Aktion Mensch annually awards the BIENE Award for particularly successful accessible Internet offers in various categories. The winners are also demonstrations of successful web design.

Current

WCAG 2.0 received recommendation status on December 11, 2008. In contrast to WCAG 1.0, they no longer focus on HTML and CSS as the most important standards of the Internet, but describe more generally how layouts, interactions, etc. a. must be designed so that the offer is barrier-free. The implementation of these guidelines for the individual technologies such as HTML, Java , Flash or PDF is the responsibility of the respective responsible institutions or companies. This means that WCAG remains open to the rapid technological developments of the Internet and new technologies can be integrated.

The WCAG were further developed; In June 2018, WCAG 2.1 was published as a W3C Recommendation (Web Standard).

The WCAG test is a test procedure for checking the accessibility of web offers. It was developed as part of the “BIK - barrier-free information and communication” project series funded by the Federal Ministry of Labor and Social Affairs and makes the requirements of the WCAG manageable.

The recommendations in detail

The individual points to be checked in WCAG 1.0 are divided into 14 groups and have three different priorities (A, AA, AAA). The WAI offers numerous support services related to WCAG in order to facilitate the implementation of the guidelines. The key points are shown in the following overview:

• clear structure of the document with headings and lists, the layout is done with CSS if possible
• the purpose or function of images and animations is described by the alt attribute
• There are text alternatives to multimedia offers, subtitles and transcription for audio and audio description for video
• Charts are described in the text or by using the longdesc attribute
• Frames have meaningful name attributes and the noframes element is used
• Tables can be read line by line if possible. Their content is also described in summary.
• Use of user-provided image maps
• Scripts , applets, etc. are barrier-free or there are barrier-free alternatives
• Tables are only used to present data.

It is also important to check the pages for conformity - the so-called validation. Appropriate software tools can at least partially be used for this purpose. However, not all aspects of conformity can be checked automatically.

In principle, the use of other technologies is not ruled out if certain principles are observed. For example, HTML, CSS and JavaScript can be used if all information is represented by HTML, CSS controls the layout and the use of JavaScript is limited to improving usability. However, if the presentation of information is integrated in such a way that the functionality of JavaScript, Java, Flash, CSS, etc. is absolutely necessary, the offer is not barrier-free. Many of the expanding technologies offer independent functionalities to improve accessibility (Java, Flash), which, however, are often not used or not supported by the assisting technology.

Overview of the 4 principles and 13 guidelines of the WCAG 2.1

Perceptibility	Text alternatives	Provide text alternatives for all non-text content so that it can be changed into other forms the user needs, such as large type, braille, symbols, or simpler language.
	Time-based media	Provide alternatives to time-based media.
	Customizable	Create content that can be presented in different ways (simpler layout) without losing information or structure.
	Distinguishable	Make it easier for users to see and hear content including separating the foreground and background.
Usability	Accessible via keyboard	Make sure that all functionalities are accessible via keyboard.
	Enough time	Give users enough time to read and use content.
	Seizures	Do not design content in ways that are known to cause seizures.
	Navigable	Provide means to help users navigate, find content, and determine where they are.
	Entry modalities	Make it easier for users to use various inputs beyond the keyboard.
Comprehensibility	Readable	Make content readable and understandable.
	Predictable	Make websites look and work predictably.
	Help with the input	Help users avoid and correct mistakes.
robustness	Compatible	Maximize compatibility with current and future user agents, including assistive technologies.

literature

• Jan Eric Hellbusch: Barrier-free web design. Practical manual for web design and graphic program interfaces . Heidelberg 2004, ISBN 3-89864-260-7
• Jan Eric Hellbusch, Kerstin Probiesch (): Understanding and implementing accessibility: Web standards for an accessible and usable Internet . Heidelberg 2011, ISBN 978-3-89864-520-1

Web links

• Guidelines for accessible web content (WCAG) 2.0 - Authorized German translation of the Web Content Accessibility Guidelines (WCAG) 2.0
• Web Content Accessibility Guidelines 2.1 June 5, 2018 (the current English version of the guidelines)
  • Web Content Accessibility Guidelines 2.0 (December 2008)
• WCAG 2.0 at a glance Easy for everyone. The offer of Aktion Mensch for a barrier-free internet.
• Winner of the Bee Prize for particularly successful barrier-free web offers

Individual evidence

1. ↑ Guidelines for Accessible Web Content (WCAG) 2.0. World Wide Web Consortium , October 29, 2009; accessed February 10, 2017 . 
2. ↑ Implementing Decision (EU) 2018/2048 of the Commission of December 20, 2018 on the harmonized standard for websites and mobile applications in support of Directive (EU) 2016/2102 of the European Parliament and of the Council , accessed on April 30, 2019
3. ↑ Article 12 of Directive (EU) 2016/2102 of the European Parliament and of the Council of October 26, 2016 on barrier-free access to the websites and mobile applications of public bodies , accessed on February 10, 2017
4. ↑ Communication from the Commission to the European Parliament pursuant to Article 294 (6) of the Treaty on the Functioning of the European Union on the Council's position with a view to adopting a European Parliament and Council directive on accessible websites and mobile applications of public Positions COM (2016) 484 final , accessed on February 10, 2017 “According to the proposal, websites of some public bodies should be made accessible across the EU by ensuring that they comply with the same technical norms and standards (Web Content Accessibility Guidelines WCAG 2.0 Level AA of the W3C - WCAG 2.0). "
5. ^ Gregor Eibl: EU directive on barrier-free access to the websites and mobile applications of public bodies. (PDF; 0.7 MB) Federal Chancellery Austria , January 31, 2017, accessed on February 10, 2017 . 
6. ↑ Ben Caldwell, Michael Cooper, Loretta Guarino Reid, Gregg Vanderheiden: Web Content Accessibility Guidelines (WCAG) 2.0. W3C, December 11, 2008, accessed December 13, 2008 . 
7. ↑ heb: New web standard for accessibility WCAG 2.0 adopted. heise online, December 12, 2008, accessed on December 13, 2008 . 
8. ↑ Guidelines for Accessible Web Content (WCAG) 2.0. In: W3C. German Disability Aid Aktion Mensch e. V., October 29, 2009, accessed October 28, 2010 . 
9. ↑ The WCAG test. The BIK project - barrier-free information and communication; accessed on April 26, 2018
10. ↑ WAI QuickTips , German translation. W3C, 2001; Retrieved November 21, 2006