Tillgänglighetskaskaden

Tillgänglighetskaskaden, or the accessibility cascade, is a concept in web accessibility that describes how accessibility issues can accumulate and impact users with disabilities. It suggests that if a website or application has multiple layers of accessibility barriers, the combined effect can be significantly more detrimental than any single barrier. Imagine a waterfall; each level of rock represents a different accessibility failure. If a user encounters one barrier, it might be navigable with effort. However, if they encounter multiple barriers in sequence, the cumulative effect can make the entire experience inaccessible.

For example, a user who relies on a screen reader might first encounter unlabeled form fields. This is a barrier. If they then navigate to a video that lacks captions, that's another barrier. If they then try to interact with a custom navigation menu that is not keyboard-navigable, that's a third barrier. For someone without a disability, these might be minor inconveniences. For a person with a disability, each of these failures adds to their cognitive load and increases the difficulty of completing their task. The more barriers present, the more likely it is that the user will abandon the site or application.

The principle of the accessibility cascade underscores the importance of addressing accessibility comprehensively rather than as a series of isolated fixes. It encourages designers and developers to consider the holistic user experience and strive for a robust and inclusive design that minimizes the potential for multiple, compounding barriers. Proactive and integrated accessibility practices are therefore crucial to avoid creating an insurmountable obstacle course for users with disabilities.