Error Tolerance

A design principle requiring that systems anticipate, prevent, and gracefully handle user errors. In accessible design, error tolerance means providing clear validation messages, allowing users to undo actions, confirming destructive operations, and ensuring that mistakes do not lead to data loss or dead ends. This is especially important for users with cognitive disabilities who may have difficulty understanding complex form requirements or multi-step processes. WCAG addresses error tolerance through success criteria on error identification, labels, and error prevention for legal and financial transactions.