Universal usability refers to designing products, services, and content to be usable by people with the widest range of abilities and disabilities. It aims to make things simple, standardized, and consistent so that they can be easily used without extra effort. Key principles of universal design include simplicity, perceptible information, tolerance for error, and low physical effort. Web accessibility guidelines like WCAG provide specific guidance on developing accessible web content by ensuring it is perceivable, operable, and robust.

1. Universal Usability

2. Usability
Usability literally means “Whether a product, service, etc. are usable
(accessible) with effectiveness, efficiency, and satisfaction by its user,
within its use of context, or not”.
Usability describes the different levels of accessibility by which, it allows a user
to get their goal easily.

3. Why it is important?
Productivity
Facilitate ease of use
Accessibility
Objective completion

4. Components of Usability
Learnability – How long it takes a user to get familiar with the interface to use
it?
Efficiency – How proficient to work with it, while interacting with product?
Memorability – Do we need to put any extra effort to memorize, for
interaction with the product?
Errors – Do error rates are higher than success rates?
Satisfaction – Did it work as it intended to do?
Utility – Did we achieve the core functionalities, for that it is designed?

5. Universal Usability
Product
Different Usability Methods and principles that cover a wide range of audience
or class of users
Design concepts are closely related to design for all.

6. Universal Design Guidelines
Simplicity – Simple to use without any difficulties among wide range of individual preferences
and abilities..
Standardization – Standard designing methods makes the application easy to use without
making extra effort.
Consistency - Maintaining consistency while designing a product increases its availability and
accessibility. With the consistent design we can put a psychological effect to use it.
Perceptible Information – Uses a variety of methods to percept information by the user with
sensory abilities.
Tolerance for Error – Robust and responsive to adverse consequences of accidental and
unintended actions.
Low Physical Effort – Minimal sustained and repetitive operations

7. Web Content Accessibility Guidelines (WCAG)
WCAG gives us specific details on how to develop accessible web content. It
provides guidance for web accessibility.
Web accessibility relies on the several components that work together.
Web content
User agent
Authorizing tools
Standards play a vital role in defining accessibility requirements for each of
these components. Some accessibility requirements are easy to meet, yet
understanding the basics of how people with disabilities use the Web helps
implement them more effectively and efficiently.

8. Accessibility Standards
Perceivable information and user interface
• Text alternatives for non-text content
• Captions and other alternatives for multimedia
• Content can be presented in different ways
• Content is easier to see and hear
Operable user interface and navigation
• Functionality is available from a keyboard
• Users have enough time to read and use the content
• Content does not cause seizures and physical reactions
• Users can easily navigate, find content, and determine where they are
• Users can use different input modalities beyond keyboard
Robust content and reliable interpretation
Content is compatible with current and future user tools

9. References
https://www.w3.org/WAI/standards-guidelines/wcag/
http://universaldesign.ie/What-is-Universal-Design/Definition-and-
Overview/
https://developer.paciellogroup.com/blog/2017/08/inclusive-design-
principle-be-consistent/
https://www.w3.org/WAI/fundamentals/accessibility-principles/