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Confidence Tuning

This guide explains how to configure confidence thresholds to balance detection sensitivity with false positive reduction.

Understanding Confidence Scores

Every Anava detection includes a confidence score indicating how certain the AI is about its analysis.

Score Ranges

RangeLabelMeaning
0-40%Very LowUncertain, likely incorrect
40-60%LowSome indicators, needs verification
60-75%MediumReasonable confidence
75-90%HighLikely correct
90-100%Very HighAlmost certain

Where Confidence Appears

  1. Object detections - Each object has a confidence score
  2. Question answers - Boolean/set answers may include confidence
  3. Overall session - Aggregate confidence for the analysis

Threshold Configuration

Profile-Level Threshold

Set in profile settings:

SettingDescriptionDefault
Confirmation ThresholdConsecutive detections before TTS fires (1-10)1

When set:

  • Requires N consecutive positive detections within a session before TTS triggers
  • ONVIF events still emit immediately (not gated)
  • Counter resets after TTS fires
  • Counter is per-session (cleared when session ends)
Reducing False Positives

Set to 2-3 to require multiple confirmations before voice response. This is especially useful in high-traffic areas where momentary detections may not warrant immediate TTS.

Object-Level Behavior

In skill configuration, each object can have:

  • Rapid Eligible - Can trigger immediate response at high confidence
  • Trigger Deep Analysis - Low confidence triggers additional analysis

Setting the Right Threshold

By Use Case

Use CaseRecommendedRationale
Weapon detection75-85%Critical but can't miss
Intrusion detection80-90%Balance speed and accuracy
PPE compliance70-80%Some tolerance acceptable
Queue monitoring60-70%Directional data OK
Analytics only50%+Capture all data

The Sensitivity Trade-off

Confidence Trade-off

Tuning Process

Step 1: Establish Baseline

  1. Set threshold to 0 (no filtering)
  2. Run for 24-48 hours
  3. Review all sessions
  4. Calculate baseline metrics

Step 2: Analyze Distribution

Review session confidence scores:

Sessions by Confidence:
├── 90-100%: 45 sessions (all correct)
├── 80-90%: 32 sessions (30 correct, 2 false positive)
├── 70-80%: 28 sessions (20 correct, 8 false positive)
├── 60-70%: 15 sessions (5 correct, 10 false positive)
└── <60%: 8 sessions (1 correct, 7 false positive)

Step 3: Set Initial Threshold

Based on analysis:

  • If 80%+ sessions are accurate at 75%, set threshold to 75%
  • Adjust based on false positive tolerance

Step 4: Monitor and Adjust

After setting threshold:

  1. Monitor for missed detections
  2. Review flagged but not alerted sessions
  3. Adjust threshold if needed

Advanced Configurations

Multi-Threshold Strategy

Use different thresholds for different responses:

ConfidenceResponse
90%+Immediate alarm + recording
75-90%Recording + email alert
50-75%Recording only
Under 50%Log for review

Implementation:

  • Create multiple profiles with different thresholds
  • Each profile triggers different VMS actions

Rapid Analysis for Critical Detections

For high-priority objects (weapons):

  1. Enable Rapid Eligible on the object
  2. High-confidence detections skip full analysis
  3. Immediate response for clear threats
  4. Full analysis continues for context

TTS Threshold

Separate from ONVIF threshold:

SettingPurpose
Profile ThresholdWhen to emit ONVIF events
TTS ConfidenceWhen to trigger voice response

Set TTS higher than ONVIF to reduce unnecessary announcements.

Troubleshooting Threshold Issues

Too Many False Positives

Symptoms:

  • VMS flooded with events
  • Action rules triggering on non-events
  • Operator alert fatigue

Solutions:

  1. Increase threshold by 5-10%
  2. Review false positives for patterns
  3. Improve skill prompts
  4. Consider pre-filter

Missing Real Events

Symptoms:

  • Known events not triggering
  • Sessions show detection but no ONVIF
  • VMS not receiving alerts

Solutions:

  1. Lower threshold by 5-10%
  2. Review missed events' confidence scores
  3. Improve prompts for clarity
  4. Consider separate high-sensitivity profile

Inconsistent Confidence

Symptoms:

  • Same scenario gives wildly different scores
  • Threshold that worked stops working

Solutions:

  1. Improve prompt specificity
  2. Add contextual information
  3. Check for environmental changes (lighting)
  4. Review recent false positives

Confidence by Object Type

Different objects may need different handling:

High-Confidence Objects

Objects where the AI is typically very certain:

  • Person (clearly visible human)
  • Vehicle (distinct shape)
  • Fire/Smoke (obvious visual)

Recommendation: Threshold 80%+

Lower-Confidence Objects

Objects that are harder to classify:

  • Weapon (context-dependent)
  • PPE items (small, similar items)
  • Behaviors (subjective)

Recommendation: Threshold 70-80% with verification

Seasonal and Environmental Adjustments

Lighting Changes

ConditionAdjustment
Winter (low light)Lower threshold 5-10%
Summer (bright)Higher threshold possible
Indoor (consistent)Standard threshold

Weather Impact

ConditionEffectAdjustment
RainReduced visibilityLower threshold
FogObscured detailsLower threshold + review
SnowReflection issuesAdjust prompts

Best Practices

Start Conservative

Begin with higher threshold and adjust down:

  • Easier to lower threshold than raise
  • Avoids initial flood of false positives
  • Builds operator trust in system

Document Changes

Keep record of:

  • Threshold changes and dates
  • Reason for change
  • Observed impact
  • Revert if needed

Regular Review

Schedule threshold review:

  • Monthly for active deployments
  • After major changes
  • Following complaints/issues