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Relevance 8/10Data and MetricsIntermediate5 min read
Class Imbalance
Class imbalance means some labels appear far less often than others.
Why it matters for annotators
Rare classes are often business-critical and easy to miss.
Visual mental model
Majority classes dominate -> minority errors hidden.
Examples (bad vs good)
Scenario: Real annotation scenario involving Class Imbalance
Bad: Labeling quickly without applying project rubric.
Good: Applying rubric criteria, documenting rationale, and escalating uncertainty.
Common mistakes
- Skipping guideline details for edge cases.
- Applying inconsistent criteria across similar samples.
- Avoiding escalation even when uncertain.
Submission checklist
- Read the latest guideline update before each batch.
- Apply rubric dimensions explicitly in each decision.
- Escalate ambiguous items with concise rationale.