Overview
Quality control in Avala ensures that annotations meet your accuracy and consistency standards before they are used for model training or analysis. The QC system provides:- Review workflows: Multi-stage review pipelines with configurable reviewers
- Annotation issues: A structured way to flag, track, and resolve problems
- Quality metrics: Quantitative measures of annotation quality
- Consensus scoring: Multi-annotator agreement for validation
Review Workflows
How Reviews Work
When an annotator completes a sequence, it enters a review stage. Reviewers examine the annotations and either approve the work or send it back for correction.Reviewer Assignment
Assign reviewers at the project level:- Go to Projects → select your project → Settings
- Under Quality Control, click Configure Review
- Add reviewers:
- Specific users: Assign named reviewers
- Team: Any member of a team can review
- Auto-assign: Distribute review work evenly across designated reviewers
- Save the configuration
Review Stages
Avala supports multi-stage review for projects that require multiple levels of quality assurance.Configuring Multiple Stages
- In project Settings → Quality Control
- Enable Multi-Stage Review
- Define each stage:
- Stage name
- Assigned reviewers
- Pass criteria (e.g., minimum accuracy threshold)
- Sequences must pass all stages to reach completed status
Performing a Review
- Navigate to your project → Review tab
- Select a sequence pending review
- Open the annotation viewer
- For each annotation:
- Verify label correctness
- Check boundary accuracy (tight fit, no missing regions)
- Confirm attributes are set correctly
- Mark the sequence as:
- Approved: Annotations meet quality standards
- Rejected: Annotations need correction (add specific feedback)
Rejection Feedback
When rejecting, provide actionable feedback:- Describe what needs to change
- Reference specific frames or objects
- Use annotation issues (see below) for persistent tracking
Annotation Issues
What Are Annotation Issues?
Annotation issues are structured flags attached to specific annotations, frames, or sequences. They create a trackable record of problems and their resolution.Creating an Issue
- In the annotation viewer, right-click an annotation or frame
- Select Create Issue
- Fill in:
- Type: Select an issue category
- Description: Explain the problem
- Severity: Low, Medium, or High
- Click Submit
Issue Types
Issue Lifecycle
- Open: Issue is created and assigned
- In Progress: Annotator is working on the correction
- Resolved: Annotator marks the issue as fixed
- Verified: Reviewer confirms the fix is correct
- Won’t Fix: Issue is acknowledged but intentionally left as-is (with a reason)
Viewing and Filtering Issues
- Project level: Go to Projects → your project → Issues tab to see all issues
- Sequence level: Issues for the current sequence appear in the viewer sidebar
- Filter by: Status, type, severity, assignee, date range
Quality Metrics
Avala tracks quality metrics at the annotator, project, and sequence level.Key Metrics
Viewing Metrics
- Navigate to Projects → your project → Analytics
- Select the metric and time range
- View breakdowns by annotator, label, or sequence
- Export metrics as CSV for external analysis
Setting Quality Targets
Define quality targets in project settings:- Go to Settings → Quality Control → Targets
- Set thresholds:
- Minimum acceptance rate (e.g., 95%)
- Maximum issue density (e.g., < 2 issues per sequence)
- Annotators and reviewers see these targets in their dashboards
- Alerts trigger when performance drops below targets
Consensus Scoring
Consensus scoring measures agreement between multiple annotators who label the same data.How It Works
- Configure consensus tasks in project settings
- Avala assigns the same sequences to multiple annotators (typically 2-3)
- Each annotator works independently
- Avala compares annotations and computes agreement scores
Agreement Metrics
Using Consensus Data
- Identify ambiguous classes: Low agreement on specific labels may indicate unclear label definitions
- Calibrate annotators: Use consensus to identify annotators who need additional training
- Build golden sets: Use high-agreement annotations as ground truth benchmarks
Best Practices
- Define clear guidelines: Write detailed annotation guidelines with visual examples before starting a project
- Start with a pilot: Run a small batch through the full QC pipeline to identify issues early
- Use multi-stage review for critical projects: Two review stages catch more errors than one
- Monitor metrics continuously: Do not wait until the project is complete to check quality
- Provide constructive feedback: Specific, actionable rejection comments help annotators improve faster
- Calibrate regularly: Use consensus tasks periodically to maintain consistency as the team grows
- Iterate on guidelines: Update annotation guidelines when recurring issues indicate ambiguity
Next Steps
- Learn about Work Batches for organizing annotation work
- Explore Sequence Statuses to understand workflow states
- Set up Team Permissions for reviewer roles