Well, if you remember, last week we have talked about Web Accessibility, its definition, significance, and statistics. If you have not read part one of this series, please refer to Accessibility and Its Importance.
This week we are going to talk about some Web Content Accessibility Guidelines and the legal aspect of accessibility.
2.1 WCAG 1.0
According to Mbipom and Harper (2009), WCAG 1.0 specifies sets of instructions that shall be followed to produce accessible websites. It contains 14 guidelines and 65 checkpoints for producing accessible websites. Guidelines provide best practices for design whereas checkpoints specify what a guideline means in practice. Checkpoints are classified in three different levels. These levels are referred to as priority levels 1,2, and 3 with priority level 3 being the most difficult level to achieve. According to W3C, these priority levels can be best described as follows:
- Priority 1: Web developers must satisfy these checkpoint. If checkpoints with this priority were not met, one or more groups will find it impossible to access information in the website.
- Priority 2: Web developers shall satisfy these checkpoints. If checkpoints with this priority were not met, one or more groups will find it difficult to access information in the website.
- Priority 3: Web developers may address these checkpoints. If checkpoints with this priority were not met, one or more groups will find it somewhat difficult to access information in the website.
After the release of WCAG 1.0, many issues were raised by researchers and interested bodies stating that the guidelines were complex and impractical. Studies also showed that developers were not able to use these guidelines because they were found to be theoretical. Checkpoints were not structured properly and were difficult to test for compliance. Thus, W3C committee decided to revise the guidelines and draft a second version. Following this, WCAG 2.0 was released in 2008 (Mbipom and Harper, 2009).
2.2 WCAG 2.0
According to Alonso, Fuertes, González and Martínez (2010), WCAG 2.0 has three layers of guidance. These layers are principles, guidelines, and success criteria. WCAG 2.0 has 4 principles, 12 guidelines, 61 testable success criteria, and a number of sufficient and advisory techniques to make web content more accessible. WCAG 2.0 were written to be testable and technique-independent. This allows the guidelines to be used for emerging and future web techniques.
The main principles of WCAG 2.0 as stated in W3C recommendations are:
- Principle 1: Perceivable – Information and user interface components must be presentable to users in ways they can perceive.
- Principle 2: Operable – User interface components and navigation must be operable.
- Principle 3: Understandable – Information and the operation of user interface must be understandable.
- Principle 4: Robust – Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.
As mentioned earlier, there is a total of 12 guidelines in WCAG 2.0. These guidelines serve as a framework for development and set goals that developers should reach to make accessible websites. These guidelines are not testable.
For each guideline, there exists a table of success criteria. These criteria are classified into levels of conformance “A”, “AA”, and “AAA”, where A is the lowest. Success criteria in WCAG 2.0 are structured in more testable sentences compared to WCAG 1.0. This makes WCAG 2.0 a better choice to test for web accessibility compliance (W3C, 2008).
For each of the guidelines and success criteria, there is a wide variety of techniques that can be used to meet or to enhance the success criteria. These techniques are classified into two categories: those that are sufficient to meet the success criteria and those that are advisory. Advisory techniques go beyond the success criteria and are intended to enhance them.
2.3 Section 508 Guidelines
One of the famous guidelines for accessibility is Section 508 Guidelines by the government of the United States. According to Takagi, Asakawa, Fukuda, and Maeda (2004), Section 508 of the Rehabilitation Act was amended in 1998 and has been in effect since June 2001. This regulation forces IT vendors to deliver accessible Websites and Web applications to federal agencies. Private sectors are encouraged to adopt the guidelines, however, they are not forced to do so. According to Section 508 government portal, the criteria for all guidelines were derived based on those from Web Accessibility Initiatives or WAI from W3C.
2.4 IBM Web Accessibility Checklist
IBM developed their own web content accessibility checklist as a contribution towards making the Internet more accessible. The current version of IBM accessibility checklist is 5.1. The checklist contains 4 levels of checkpoints. Levels are given numbered values from 1 to 4, with 1 being the lowest.
IBM accessibility checklist is comparable to WCAG 2.0. IBM checklist can be used side by side with WCAG 2.0. Both guidelines highlight the importance of using alternative texts to non-text content. IBM accessibility checklist as well as WCAG 2.0 emphasise the importance of using captions for pre-recorded media. A list of similarities and differences is available on IBM portal. IBM checklist has 36 checkpoints compared to 61 success criteria in WCAG 2.0 Every checkpoint in IBM has a WCAG 2.0 equivalent except 2 checkpoints. These are image-map and text-only page checkpoints 1.1c and 4.2a, respectively (IBM, 2010).
2.5 Publicly Available Specifications (PAS 78:2006)
British Standards Institution has published a Publicly Available Specifications PAS 78:2006 for web content accessibility. The specifications make use of the W3C guidelines. PAS 78:2006 outlines good practice in commissioning websites that are accessible to and usable by disabled people. IT also gives recommendations for management or parties upholding accessibility issues as well as recommendations to involve disabled people in the processes of developing and using compliance testing tools. These practices are applicable to public as well as organizations (BSI, 2006).
2.6 Stanca Act
This act was put forward by the Italian government to ensure disabled can have access to ICT. The law enforces accessibility and usability on all operational and organizational websites. The act name is derived from the name of the current Minister of Innovation and Technologies and was approved in 2004. The law does not apply only to the Internet. It applies to all communication and electronic systems. Enforcement regulations were approved in 2005 stating that all Public Administrations are required to modify their websites to be accessible within a period of 12 months. The law defines guidelines for accessibility and usability for public and organizations (BrailleNet, 2011).
2.7 Barrierefreie Informationstechnik-Verordnun (BITV)
German law of equality for handicapped people (BGG) forms the basis for the BITV guidelines. It sets rules to make internet pages barrier-free for the disabled. These guidelines also make reference of the W3C guidelines. As stated in the BITV portal, the guidelines are mandatory for all German federal websites. BITV guidelines follow W3C guidelines closely as mentioned by BITV portal (BITV, 2011).
2.8 Japanese Industrial Standards (JIS)
Japanese Industrial Standard for Web accessibility or Web Content JIS as referred to sometimes was released in 2005. JIS guidelines are not mandatory, however, several organizations are showing growing interest in these standards nowadays. The standards try to comply to all W3C guidelines (Webaim, 2011).
In this post, I have talked about some of the most commonly used guidelines for web content accessibility. Some of them were specific to some country, whereas others were made public.
Next time I will be talking about some of the tools that could be used for accessibility evaluation. So, stay tuned!
Mbipom, G., & Harper, S. (2009). The Transition From Web Content Accessibility Guidelines 1.0 to 2.0: What This Means for Evaluation and Repair. Paper presented at the 27th ACM International Conference on Design of Communication, Bloomington, Indiana, USA.
Alonso, F., Fuertes, J., González, Á., & Loïc, M. (2010). Evaluating Conformance to WCAG 2.0: Open Challenges Lecture Notes in Computer Science, 6179, 417-424
W3C. (2008). Web Content Accessibility Guidelines (WCAG) 2.0. Retrieved 08-04, 2011, from http://www.w3.org
Takagi, H., Asakawa, C., Fukuda, K., & Maeda, J. (2004). Accessibility designer: visualizing usability for the blind. Paper presented at the 6th international ACM SIGACCESS Conference on Computers and Accessibility.
IBM. (2010). Web checklist. Retrieved 07-05, 2011, from http://www-03.ibm.com
British Standards Institution. (2006). Publicly Available Specifications (PAS 78:2006): BSI Group.
BrailleNet. (2011). Stanca Act. Italy.
WebAim. (2011). World Laws: Asia (Hong Kong and Japan). Retrieved 10-05, 2011, from http://webaim.org