One of the strengths of open access materials is the ability to improve a work’s accessibility or building a work with accessibility and usability in mind. Accessibility means someone with a disability must be able to obtain information as fully, equally, and independently as a person without a disability. User groups with special needs and disabilities can include blind users who use screen reader software, low vision and/or colorblind users, users with low technology access or skill levels, and low-mobility users who use only keyboard controls. 

Web Content Accessibility Guidelines (WCAG) have become the standard for digital accessibility. WCAG provides guidelines and success criteria revolve around four basic principles:  

•     Perceivability is concerned with whether information is consumable and visible to all users. Information should be displayed in different ways, such as providing text transcripts for audio or alt text for images.
•     Operability applies to whether users can effectively operate and navigate a website with a variety of tools. For example, providing proper headings or descriptive linking would help make webpages more compatible with screen readers and voice recognition software.
•     Understandable is concerned with whether operations and information are clear and concise. So here, descriptive instructions and unambiguous error messages would help make a page more understandable to users needing to complete a specified task.
•     Robust when they can be used with a multitude of browsers, devices, and assistive technologies.