Legally and ethically we need to present the best Website format for our users that is accessible, usable and follows the principles of universal design. LIbGuides are web pages and should follow web design standards.
Usability is about designing products to be effective, efficient, and satisfying. Usability includes user experience design. This may include general aspects that impact everyone and do not disproportionately impact people with disabilities. Usability practice and research often do not sufficiently address the needs of people with disabilities. (W3C)
Universal Design, according to the Centre for Excellence in Universal Design (2014), is the design and composition of an environment so that it can be accessed, understood and used to the greatest extent possible by all people regardless of their age, size, ability or disability. An environment (or any building, product, or service in that environment) should be designed to meet the needs of all people who wish to use it. This is not a special requirement for the benefit of only a minority of the population. It is a fundamental condition of good design. If an environment is accessible, usable, convenient and a pleasure to use, everyone benefits.
Understanding the relationship between accessibility and usability is helpful in integrating accessibility into design processes and service practices.
When people talk about both usability and accessibility, it is often to point out how they differ. Accessibility often gets pigeon-holed as simply making sure there are no barriers to access for screen readers or other assistive technology in regard to usability, while usability usually targets everyone who uses a site or product, without considering people who have disabilities. In fact, the concept of usability often seems to exclude people with disabilities, as though just access is all they are entitled to. What about creating a good user experience for people with disabilities—going beyond making a Web site merely accessible to make it truly usable for them? (Quesenery, Whitney, "Universal usability: Putting people at the center of design." UX Matters)
"Consistency is King" (Talia Richards of SpringShare)
While we meet the legal definition of accessible, we do not meet standards for usability. Some of the issues are the inconsistent look of our guides, long text, misuse of font attributes, alt statements, infographics, use of library jargon and much more.