What is Accessibility Testing?
Accessibility testing is part of usability testing. It allows us to collect information about how the application is used by people with certain types of disabilities, and its goal is to make the benefits of the Internet accessible for individuals, businesses, and society. Success criteria are organized around the following Four Principles of Accessibility:
- Perceivability — Information and user interface components must be presentable to users in ways they can perceive. Users must be able to take in the information being presented through at least one of their senses.
- Operability — User interface components and navigation must be operable. Users must be able to interact with the interface, so the interface cannot require an action that a user cannot perform.
- Understandability — Information and the operation of the user interface must be easy to comprehend. Users must be able to understand the information as well as the operation of the user interface.
- Robustness — Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies. Users must be able to access the content as technologies advance. As technologies and user agents evolve, the content should remain accessible.
If any of these are not true, users with disabilities will not be able to use the application or site. International web standards define what is needed for accessibility. Major search engines, such as Google, are promoting the SEO benefits of web accessibility techniques. Web services and pages will be promoted better if they correspond to WCAG standards.
WCAG Accessibility Testing
Electronic accessibility has three levels according to WCAG 2.1 standards
WCAG 2.1 Level A: Minimal Compliance
These conformance requirements prohibit elements that would make the website inaccessible. Websites that do not at least meet WCAG 2.0 A are impossible or exceedingly difficult for people with disabilities to use.
Some notable WCAG 2.0 Level A requirements include:
- No keyboard traps
- Ability to navigate with a keyboard
- Non-text content alternatives
- Video captions
- Meaning conveyed through at least two senses
Level A sets a minimum level of accessibility and does not achieve broad accessibility for many situations. For this reason, UC recommends AA conformance for all web-based information.
WCAG 2.1 Level AA: Acceptable Compliance
This conformance level is used in most accessibility rules and regulations around the world, including the ADA. To meet WCAG 2.1 Level AA conformance, the website must be usable and understandable for the majority of people with or without disabilities. The meaning conveyed and the functionality available must be the same.
Some notable WCAG 2.0 Level AA requirements include:
- Color contrast is, in most instances, at least 4.5:1
- Alt text or a similar solution is used for images that convey meaning
- Navigation elements are consistent throughout the site
- Form fields have accurate labels
- Status updates can be conveyed through a screen reader
- Headings have a logical order
WCAG Level AAA: Optimal Compliance
Compliance at this level makes your site accessible to the maximum number of users and makes their experience easy. While this level of conformance would be ideal to make the web experience truly equal for all users, W3 explains “it is not recommended that Level AAA conformance be required as a general policy for entire sites because it is not possible to satisfy all Level AAA Success Criteria for some content” (see Understanding Levels of Conformance and Conformance Requirements).
Some notable WCAG 2.0 AAA requirements include:
- Sign language interpretation for audio or video content
- Color contrast is at least 7:1 (in most instances)
- Timing is not an essential part of any activity
- Context-sensitive help is available
Conformance at higher levels indicates conformance at lower levels. For example, by conforming to AA, a web page meets both the A and AA conformance levels.
Webaim.org provides a WCAG 2 checklist that provides instructions for compliance that are easy to understand and implement.
How to Do Accessibility Testing for Websites and What Tools to Use
We’ve compiled a list of accessibility testing tools that can be useful to start your testing process:
Web services or web pages should meet search engines’ requirements and standards in order to be indexed in search results. First, your project should be tested technically using the following browser plug-ins:
- The ‘Lighthouse’ extension from Google to check the current state of your website. Lighthouse generates reports with practical advice on how to fix issues.
- The ‘Wave’ extension from WebAIM to identify areas in which a site can improve according to WCAG standards. Wave generates reports with a list of issues and advice for what to change.
Your development team defines what WCAG level should be adhered to on the project. Your QA team should prepare specific test cases or test scenarios according to Web Content Accessibility Guidelines in order to cover the following sections:
Section 1 – User interface components must be presentable to users in ways they can perceive
- Text Alternatives
Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols, or simpler language
- Time-Based Media
Provide alternatives for time-based media
Create content that can be presented in different ways (for example, in a simpler layout) without losing information or structure
Make it easier for users to see and hear content, including by separating foreground from background.
Section 2 – User interface components and navigation must be operable
- Keyboard Accessibility
Make all functionality available through a keyboard
- Sufficient Time
Provide users with enough time to read and use content
- Seizures and Physical Reactions
Do not design content in a way that is known to cause seizures or other physical reactions
Provide ways to help users navigate, find content, and determine where they are
- Input Modalities
Make it easier for users to operate functionality through various inputs beyond the keyboard
Section 3 – Information and the operation of the user interface must be perceivable
Make text content readable and understandable
Make web pages appear and operate in predictable ways
- Input Assistance
Help users avoid and correct mistakes
Section 4 – Content must be robust enough that it can be interpreted by a wide variety of user agents, including assistive technologies.
Maximize compatibility with current and future user agents, including assistive technologies such as screen readers
A specific screen reader should be selected according to project requirements from the list below:
- NVDA screen reader for webpages and native applications on Windows
- JAWS screen reader for webpages on Windows
- Apple VoiceOver for OS X
- Built-in screen reader on OS X
- Screen Reader for Chrome
Why is Accessibility Testing Important?
Accessibility testing for websites is one of the key elements in platform/application development. The benefits of accessibility testing are enormous; it helps companies expand their user base by providing visually, hearing, and mobility impaired people with access to online resources and technology. However, accessibility isn’t just about increasing your market share or attracting more users; it’s also for providing equal opportunities to everyone. By increasing web accessibility, we’ll ultimately help ensure that everyone can navigate freely in a digital world.
Author: Vital Shtaniuk