Web Usability

Usability is not exclusive to the web. It refers to the relationship between tools and their users, so it is applicable to practically any field. Usability is usually defined as the measure of the ease with which particular people can employ a particular tool.

Within the web development process, usability is the set of techniques used during the design of the web site in order to improve the ease of use to everybody, including those with disabilities. Web usability is based on two main principles:

• Visitors only see what they need: Internet users don’t read in detail, they skim the web trying to find what they are really interested in. If they can’t find what they are looking for, they will leave your site.
• Visitors are impatient: They want to access the relevant information as soon as possible. If they can’t find what they are looking for quickly, they will leave your site.

Accessibility vs Usability

Web accessibility and usability both improve satisfaction, effectiveness, and efficiency of users. But while accessibility is aimed at making the web site open to a wider user population, usability is aimed at making the target population of the web site happier, more efficient, more effective.
Accessibility covers technical issues; usability is experiential. It is about the user’s experience when accessing a web site. Usability is very much like quality: you typically notice it only when it is missing.

Usability Factors

Web usability is about making your web site in such a way that your site users can find what they're looking for quickly and efficiently. A usable web site can reap huge benefits on to your website and your business:

"A web usability redesign can increase the sales/conversion rate by 100%" (source: Jakob Nielson2)

Web usability is not just about making sure everything on the site works, but also how quickly and easily visitors are able to make use of the site. Web usability covers download time, page layout, graphics, animation, navigation, information architecture, search, etc... it can only be measured by the end user’s experience and satisfaction. Here are some examples:

• The web site should be easy to find by search engines.
  
• The web site should be quick to download.
  
• The user should easily find the information he/she is looking for.
  
• The services offered should be easy to access and understand.
  
• The web page layout and design should be consistent throughout the site.
  
• The site should has a logical structure and efficient navigation.
  
• Explanations should be provided on how the site is organized.
  
• The user should be able to interact with the site and provide feedback.
  
• The site should offer some search features.

WCAG

Web Content Accessibility Guidelines (WCAG) are part of a series of Web accessibility guidelines published by the W3C's Web Accessibility Initiative (WAI). They consist of a set of guidelines on making content accessible, primarily for disabled users, but also for all user agents, including highly limited devices, such as mobile phones.

Web "content" generally refers to the information in a Web page or Web application, including text, images, forms, sounds, and such. More specific definitions are available in the WCAG documents.

WCAG technical documents are developed by the Web Content Accessibility Guidelines Working Group (WCAG WG), which is part of the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI). Other accessibility guidelines include the Authoring Tool Accessibility Guidelines (ATAG) and the User Agent Accessibility Guidelines (UAAG).

The WCAG are intended for all Web content developers (page authors and site designers) and for developers of authoring tools. Following them will make Web content more available to all users, whatever user agent they are using (desktop browser, voice browser, mobile phone, etc.) or constraints they may be operating under (noisy surroundings, hands-free environment, etc.). These guidelines do not discourage content developers from using images, video, etc., but rather explain how to make multimedia content more accessible to a wide audience.

There are currently two versions of the WCAG. WCAG 1, contains 14 main guidelines with a total of 65 in all. WCAG 2, has reorganized and combined many of the WCAG 1 guidelines to create 21 new ones.

Each guideline has a one or more ‘checkpoints’ which developers should consider to ensure the accessibility of a Web page. Each checkpoint has a priority level based on its impact on Web accessibility. The WCAG provides a number of examples and techniques to help Web developers to implement the guidelines.

WCAG Priority Levels

Each checkpoint has a priority level assigned by the Working Group based on the checkpoint's impact on accessibility:

[Priority 1]
A Web content developer must satisfy this checkpoint. Otherwise, one or more groups will find it impossible to access information in the document. Satisfying this checkpoint is a basic requirement for some groups to be able to use Web documents.

[Priority 2]
A Web content developer should satisfy this checkpoint. Otherwise, one or more groups will find it difficult to access information in the document. Satisfying this checkpoint will remove significant barriers to accessing Web documents.

[Priority 3]
A Web content developer may address this checkpoint. Otherwise, one or more groups will find it somewhat difficult to access information in the document. Satisfying this checkpoint will improve access to Web documents.

WCAG Conformance

The WCAG guidelines have three levels of conformance:

Conformance Level "A": all Priority 1 checkpoints are satisfied. This is known as 'WCAG A' compliant.

Conformance Level "Double-A": all Priority 1 and 2 checkpoints are satisfied. This is known as 'WCAG AA' compliant.

Conformance Level "Triple-A": all Priority 1, 2, and 3 checkpoints are satisfied. This is known as 'WCAG AAA' compliant.

Note that conformance levels are even spelled out in text so they may be understood when rendered to speech.

In the following posts, insha Allah, we will go through the main guidelines of different versions of the WCAG.

Web Accessibility

Reference to my last post, Web Standards Movement, Web Accessibility is a very important issue behind the Web standards: not only does it mean allowing the Web to be fully used by people with disabilities, it also means allowing people with unconventional browsers to have access to any web page.

The DDA (Disability Discrimination Act) states that service providers must not discriminate against disabled people. A web site is regarded as a service and therefore falls under this law, and as such must be made accessible to everyone.

Accessibility involves two key issues: first, how users with disabilities access electronic information, and second, how web content designers and developers enable web pages to function with assistive devices used by individuals with disabilities.

For the user with a disability, the challenge is to identify tools that provide the most convenient access to web-based and other electronic information. For the web content designer/developer, the challenge is to remove the obstacles that prevent accessibility tools from functioning effectively. In many cases, these challenges are relatively simple to overcome, but sometimes the solutions require some additional thought and effort.

Yes.. Accessibility Has Standards

Accessibility standards help designers and developers of web content identify and address accessibility issues.

The Web Content Accessibility Guidelines (WCAG) from the W3C represented the first major effort to establish guidelines for accessible design. This standard consists of 14 guidelines, each with three checkpoint levels for web developers to meet: Priority One, Priority Two, and Priority Three.

In individual countries, national standards emerged later. Section 508 of the Federal Rehabilitation Act in the United States is based on WCAG Priority One checkpoints. These same checkpoints serve as the basis for standards in Australia, France, Germany, and many other countries. The Common Look and Feel standard in Canada and Guidelines for U.K. Government Web Sites in the United Kingdom are based on Priorities One and Two of the WCAG.

The World Wide Web Consortium (W3C)'s Web Accessibility Initiative (WAI) is an effort to improve the accessibility of the World Wide Web (WWW or Web) for people using a wide range of user agent devices, not just standard web browsers. This is especially important for people with physical disabilities which require such devices to access the Web.

Web Standards Movement

Back in early '96, the Web was no more than a long list of text documents linked together by "a" tags, displaying an occasional image from time to time. In those days, there wasn't much of a need for standardization as we mean it today.

Nowadays, in this period of tremendous growth, the Web needs a guidance to realize its full potential. Web standards are this guidance. These standards help ensure that everyone has access to the information we are providing, and also make web development faster and more enjoyable.

Web standards are technologies, established by the World Wide Web Consortium (W3C) and other standards bodies, that are used to create and interpret Web-based content. These technologies are designed to future-proof documents published on the Web and to make those documents accessible to as many as possible.

Currently, most of the standards have been officially implemented by the W3C. One standard, however, originated at another organization, called ECMA.

The European Computer Manufacturers Association (ECMA) is an organization officially founded in 1961 in order to meet the need for standardizing computer operational formats, including programming languages and input/output codes. In 1994, the organization’s name was changed to the ECMA - European Association for Standardizing Information and Communication Systems, in order to reflect its broader range of activities.

W3C Standards

HTML

Hyper Text Markup Language (HTML) is widely used on the Web for adding structure to text documents. Browsers interpret these documents, representing the structure in media-specific ways to the user.

XML

Extensible Markup Language (XML) is a markup language like HTML, but instead of having a single, fixed set of elements, it allows you to define your own - or use a set made by someone else.

XHTML

XHTML is a reformulation of HTML as an XML application. XHTML 1.0 can be seen as ideologically coming from HTML 4.01, and being technically stricter because of XML’s influence.

CSS

Cascading Style Sheets (CSS) is a mechanism for changing the appearance of HTML or XML elements, by assigning styles to element types, self-defined classes of elements or individual instances.

DOM

The Document Object Model (DOM) allows the full power and interactivity of a scripting language, such as JavaScript, to be exerted on a web page. In programming terms, the DOM is an Application Programming Interface (API) for interacting with web pages.

ECMA Standards

ECMAScript

ECMAScript is a standardized object-based scripting language, based largely on Netscape’s JavaScript. The main use of ECMAScript is to manipulate the objects in web pages which are specified by the DOM. This lets web developers implement such effects as animated text, graphic roll-overs, and pages that change based on user input without having to be reloaded.

Why should you care?

• The structural information present in compliant documents makes it easy for search engines to access and evaluate the information in those documents, and they get indexed more accurately.

• Standards are written so that old browsers will still understand the basic structure of your documents. Even if they can’t understand the newest and coolest additions to the standards, they’ll be able to display the content of your site.
  

• Compliant documents can easily be converted to other formats, such as databases or Word documents. This allows for more versatile use of the information within documents on the World Wide Web, and simplified migration to new systems - hardware as well as software - including devices such as TVs and PDAs.

• Accessibility to a wide audience is guaranteed. Web pages are accessible by people using browsers other than the usual ones - including voice browsers, Braille browsers, hand-held browsers, teletext displays, and other unusual output devices.

• Web standards offer a set of rules that every Web developer can follow, understand, and become familiar with. When one developer designs a site to the standards, another will be able to pick up where the former left off.

As you see, using web standards will let you build websites in a way that saves time and money for the developer and provides a better experience for the visitor. More information is available at the W3C and the Web Standards Project.