Dunning-Kruger Effect

A cognitive bias in which people with limited knowledge or competence in a domain overestimate their ability, while those with greater expertise tend to underestimate their relative skill. In accessibility, the Dunning-Kruger effect appears when developers or designers believe a product is accessible because basic checks pass, without recognizing the depth of expertise required to evaluate complex interactive components. Accessibility training, hands-on auditing, and exposure to assistive technology use by disabled users are effective countermeasures because they reveal the gap between perceived and actual competence.