Advanced Evaluation

LLM-as-a-Judge techniques for evaluating AI outputs. Not a single technique but a family of approaches - choosing the right one and mitigating biases is the core competency.

When to Activate

• Building automated evaluation pipelines for LLM outputs
• Comparing multiple model responses to select the best one
• Establishing consistent quality standards
• Debugging inconsistent evaluation results
• Designing A/B tests for prompt or model changes
• Creating rubrics for human or automated evaluation

Core Concepts

Evaluation Taxonomy

Direct Scoring: Single LLM rates one response on a defined scale.

• Best for: Objective criteria (factual accuracy, instruction following, toxicity)
• Reliability: Moderate to high for well-defined criteria

Pairwise Comparison: LLM compares two responses and selects better one.

• Best for: Subjective preferences (tone, style, persuasiveness)
• Reliability: Higher than direct scoring for preferences

Known Biases

Bias	Description	Mitigation
Position	First-position preference	Swap positions, check consistency
Length	Longer = higher scores	Explicit prompting, length-normalized scoring
Self-Enhancement	Models rate own outputs higher	Use different model for evaluation
Verbosity	Unnecessary detail rated higher	Criteria-specific rubrics
Authority	Confident tone rated higher	Require evidence citation

Decision Framework

Is there an objective ground truth?
├── Yes → Direct Scoring (factual accuracy, format compliance)
└── No → Pairwise Comparison (tone, style, creativity)

Quick Reference

Direct Scoring Requirements

1. Clear criteria definitions
2. Calibrated scale (1-5 recommended)
3. Chain-of-thought: justification BEFORE score (improves reliability 15-25%)

Pairwise Comparison Protocol

1. First pass: A in first position
2. Second pass: B in first position (swap)
3. Consistency check: If passes disagree → TIE
4. Final verdict: Consistent winner with averaged confidence

Rubric Components

• Level descriptions with clear boundaries
• Observable characteristics per level
• Edge case guidance
• Strictness calibration (lenient/balanced/strict)

Integration

Works with:

• context-fundamentals - Effective context structure
• tool-design - Evaluation tool schemas
• evaluation (foundational) - Core evaluation concepts

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For detailed implementation patterns, prompt templates, examples, and metrics: references/full-guide.md

See also: references/implementation-patterns.md, references/bias-mitigation.md, references/metrics-guide.md