Constructing a POUR Website
Even if web content is universally perceivable and operable, it still must be understandable in order to be accessible. Understandability touches on usability—while consideraing a wider range of use cases and that users with cognitive or learning disabilities might be more impacted by content that is not highly understandable.
Web content should be written as clearly and simply as possible, while also considering its target audience. Understandably, The Atlantic is written to a different reading level than Highlights for Children. Since authors cannot always know the exact characteristics of their audience, one strategy is to begin with simpler language in the first few paragraphs and then increase in complexity farther down, as the subject requires.
It's also important to identify the language in which web content is written using the lang attribute in the page code. This better ensures that the content will be presented appropriately and read audibly by screen readers in the correct language.
Alternative or supplemental representations
Alternative representations of textual information—illustrations, videos, animations, audio, etc.—can often increase understandability. Some users with more severe cognitive disabilities or people with reading disabilities, may need these alternative formats for comprehension. Complex or unfamiliar terms, abbreviations, and acronyms should be explained. Summaries or abstracts can make lengthy content more understandable.
Beyond text, users must be able to understand how site navigation and other interactions work. On static websites, the interaction may be limited to hypertext links. More complex web content can require multiple steps, decisions along the way, forms to complete, confirmations, and so on. Every point of interaction deserves attention to give users the best experience possible. If understanding breaks down at any point of the interaction, the user will not be able to complete the task.
Navigation should be consistent and predictable. Interactive elements such as form controls and widgets should be predictable and clearly labeled.