What is Error proofing?
Error proofing (or mistake-proofing) is the practice of designing systems so that errors are impossible to make or immediately detectable when they occur. It draws from the Japanese manufacturing concept of poka-yoke and applies it to behavioral design.
How it works
Error proofing operates at three levels: prevention (making the error physically impossible, like a USB-C plug that cannot be inserted wrong), detection (alerting the user immediately when an error occurs, like a form field that highlights invalid input in real time), and mitigation (limiting the consequences when errors happen, like auto-save that preserves work after a crash). The best error proofing is invisible: users never notice that a mistake was prevented.
Applied example
A medical system that requires scanning a patient’s wristband before administering medication prevents wrong-patient errors at the point of action rather than relying on nurses to remember to double-check in a hectic ward.
Why it matters
Error proofing is more effective than training or warnings because it works at the system level rather than depending on human vigilance, which is inherently unreliable under stress and fatigue.
