Design to prevent errors proactively.
Prioritize structural prevention over post-error recovery.
Contents 4. System Behavior & Workflow Logic 4. Error Prevention
How mistakes are avoided.
First, ask yourself
“Is it easier for users of your system to perform correct actions than incorrect ones?”
Mission statement
Ensure users avoid mistakes by constraining risky actions while avoiding unnecessary restriction.
Key heuristics Error Prevention
- Design must prevent errors structurally, not rely on recovery.
- Impossible or unsuccessful configurations must be structurally constrained.
- Correct and safe actions must require the least effort.
- Potential errors must surface at the earliest viable moment.
- Hidden or invisible modes must be eliminated or minimized.
- Protective friction must scale with consequence severity.
- Confirmation dialogs must be rare and contextually justified.
- Exploration must be safe and penalty-free.
- Defaults and automation must minimize harm and clarify consequences.
Executive brief
The system must prevent errors by shaping actions before mistakes occur.
Core questions Error Prevention
“Does the system make correct actions easy and errors hard or impossible?”
“Is doing the right thing the path of least resistance?”
Focus areas
Constraint-first
“What invalid states are blocked rather than corrected later?”
“What actions are structurally impossible by design?”
Risk-aware
“Are dangerous actions harder to perform than safe ones?”
“Is friction calibrated to the level of risk?”
Workflow-aware
“Where in the workflow could errors occur?”
“Is prevention happening early enough? How are errors prevented?”
AI-aware
“Does automation reduce errors, or create new failure modes?”
“Are predictions constrained to safe outcomes?”
UX directives Error Prevention
Eliminate invalid states through constraint.
Prevent users from entering configurations that cannot succeed.
Make safe and correct actions easiest to perform.
Design workflows so desirable behavior requires the least effort.
Surface potential errors at the earliest viable moment.
Provide validation before consequences escalate.
Eliminate or minimize hidden modes.
Ensure users are not required to remember invisible states to avoid errors.
Adjust safeguards according to consequence severity.
Increase friction proportionally for high-risk actions.
Use confirmation dialogs sparingly and meaningfully.
Avoid habituating users to dismiss warnings automatically.
Allow safe exploration without penalty.
Design guardrails that protect without discouraging learning.
Ensure defaults and automation reduce error risk.
Design automated behavior to minimize harm and clarify consequences.
Executive summary
- Error Prevention is structural constraint, not reactive correction.
- It eliminates invalid states and makes safe actions the path of least resistance.
- The system must surface risk early and prevent escalation before consequences occur.
- Safeguards must scale with severity while avoiding habitual, meaningless warnings.
- Hidden modes and invisible conditions are liabilities that invite error.
- Error Prevention succeeds when harmful outcomes are difficult to produce and safe exploration remains possible.
Success indicators
- The interface prevents invalid or impossible actions.
- Safe and correct actions are the easiest to perform.
- Potential errors are identified before they cause problems.
- High-risk actions require additional confirmation or safeguards.
- Users can explore and try actions without causing harm.
One-line summary
Before errors occur, the system must quietly prevent them.