Perspective

Testing errors means testing recovery

Deliberately make realistic mistakes and find out whether the interface helps a person continue.

A test that confirms an error appears is incomplete.

Make realistic mistakes

Leave required fields empty, use an invalid format, choose conflicting options, submit expired information and trigger other errors the real workflow allows.

Find the error

Check whether the problem is identified in text, not colour alone, and whether assistive technology can discover it.

Understand the error

Ask whether the message says what is wrong in language appropriate to the audience.

Recover

Follow the instructions. Confirm the person can correct the problem without losing valid work unnecessarily and can tell when the correction succeeded.

Test consequential actions

For legal, financial, data-changing or similarly consequential tasks, check the applicable review, confirmation and reversal requirements rather than treating them like an ordinary validation message.

What a pass establishes

The errors you deliberately exercised were identifiable and recoverable in the tested flow.

What it does not establish

It does not prove every error state exists, every message is understandable to every user, or the overall task has reasonable cognitive load.

Follow the evidence trail

Start with the recovery barrier → try the errors Lab → compare the observed cause with WCAG 2.2 Input Assistance.