> ## Documentation Index
> Fetch the complete documentation index at: https://patterns.heurilens.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Nielsen Heuristics
> Heurilens interprets Nielsen’s 10 heuristics as measurable product signals — turning usability principles into detectable UX patterns.
## Why Nielsen is the heart of Heurilens
Nielsen’s heuristics are timeless because they describe **human behavior** — not design trends.
Heurilens is built on the same principle:
**A UX issue only matters if it leaves a trace in user behavior.**
So instead of treating heuristics as a checklist,
we treat them as **signal sources**:
* what breaks on the interface
* how users react
* which product signals appear
* which Heurilens modules detect it
## How Heurilens makes heuristics measurable
We look for hesitation, misclicks, scanning loops, exits, and stalled progress.
Each trace aligns with one or more Nielsen heuristics (and often overlaps).
Repeated traces form recognizable UX patterns (e.g., hierarchy failure, feedback gaps).
Heurilens produces section-based findings, impact context, and fix directions.
## The 10 heuristics, translated into signals
Below, each heuristic is presented through the lens of **what users do** when it breaks.
Users need immediate confirmation that the system understood their action.
**When this breaks, users:**
* repeat clicks
* pause after actions
* wait without confidence
**Observable signals**
* delayed or missing feedback
* repeated interactions
* hesitation after submit
**Heurilens modules**
* Interaction Design
* User Flow
* Forms CRO
The interface must speak the user’s language and mental model.
**When this breaks, users:**
* reread content
* misinterpret actions
* scan without committing
**Observable signals**
* rapid scrolling
* secondary-first clicks
* content skipping
**Heurilens modules**
* UX Writing
* Information Scent
* Persona Alignment
Users must feel safe to explore and recover.
**When this breaks, users:**
* hesitate before irreversible actions
* abandon after mistakes
* backtrack excessively
**Observable signals**
* exits near critical steps
* abandonment after errors
* undo-seeking behavior
**Heurilens modules**
* Emotional Design
* Forms CRO
* UX Risks
Users rely on learned patterns to move quickly.
**When this breaks, users:**
* slow down
* make incorrect assumptions
* lose confidence
**Observable signals**
* misaligned clicks
* repeated corrections
* hesitation across sections
**Heurilens modules**
* Consistency
* Visual Hierarchy
* Interaction Design
Preventing errors matters more than explaining them.
**When this breaks, users:**
* encounter friction mid-task
* abandon silently
* lose momentum
**Observable signals**
* repeated validation loops
* form drop-offs
* error-triggered exits
**Heurilens modules**
* Forms CRO
* UX Risks
* Accessibility
Users should not have to remember information across steps.
**When this breaks, users:**
* re-scan interfaces repeatedly
* forget previous context
* loop through navigation
**Observable signals**
* navigation loops
* delayed decisions
* repeated scanning
**Heurilens modules**
* Information Architecture
* Information Scent
* Cognitive Load
Different users move at different speeds.
**When this breaks, users:**
* take longer paths
* feel constrained
* disengage despite familiarity
**Observable signals**
* inefficient navigation
* delayed task completion
* friction without errors
**Heurilens modules**
* User Flow
* Technical UX
* Persona Alignment
Clarity must win over density.
**When this breaks, users:**
* struggle to prioritize
* feel overwhelmed
* delay interaction
**Observable signals**
* attention fragmentation
* rapid scanning
* delayed first interaction
**Heurilens modules**
* Visual Hierarchy
* First Impression Breakdown
* Cognitive Load
Errors must feel recoverable, not punishing.
**When this breaks, users:**
* exit immediately
* avoid retrying
* restart processes
**Observable signals**
* exits after errors
* repeated failed attempts
* abandonment without recovery
**Heurilens modules**
* Forms CRO
* Emotional Design
* Interaction Design
Help should reduce uncertainty at decision points.
**When this breaks, users:**
* pause longer
* search externally
* abandon unresolved tasks
**Observable signals**
* long hesitation
* external navigation
* delayed completion
**Heurilens modules**
* Trust Signals
* SEO UX
* Information Architecture
## Why heuristics overlap (and why that’s good)
Most UX failures don’t belong to a single heuristic.
They appear as **clusters**:
* a hierarchy issue can create cognitive load
* weak feedback can create emotional risk
* unclear writing can break information scent
Heurilens is designed to detect these overlaps and show the **dominant failure pattern**.
## Related patterns
Heuristics become measurable through metrics.
Many heuristic failures compound into overload.
Standards create speed and confidence.
Small heuristic breaks become long-term product risk.
Run an analysis and see how Nielsen heuristics appear as real user signals.