LLM Classification Validator

The LLM classification validator is a five-dimension framework for testing LLM outputs.

Companion blog post: Validating LLM-Generated Control Mappings Beyond Aggregate Accuracy (Cloud Security Alliance)

For a detailed explanation of the methodology, see docs/METHODOLOGY.md.

The five dimensions

1. Coherence — Do multiple runs (or multiple raters) agree? Inter-rater reliability via Cohen's kappa, Fleiss' kappa, and bootstrap confidence intervals.

2. Consistency — Do outputs satisfy structural and semantic rules? Checks that labels exist in the target taxonomy, hierarchies are internally consistent, and required fields are present.

3. Convergent validity — Does the LLM's mapping converge with an independently derived reference? Compares LLM labels against a transitive mapping through a third framework using kappa and Jaccard similarity.

4. Adversarial discrimination — Can the LLM tell similar things apart? Minimal pairs that differ in one critical dimension, plus ambiguous inputs with multiple acceptable answers.

5. Stability and sensitivity — Same input, same answer? Changed input, changed answer? Paraphrase invariance and perturbation sensitivity.

Each dimension produces a PASS / MARGINAL / FAIL verdict against configurable thresholds. An orchestrator consolidates all dimensions into a single evaluation report.

Installation

pip install -e .

# With development dependencies:
pip install -e ".[dev]"

Quick start

Coherence

from llm_classification_validator.coherence import run_coherence_analysis

raters = {
    "run_1": ["A", "B", "A", "C", "B"],
    "run_2": ["A", "B", "A", "C", "A"],
    "run_3": ["A", "B", "B", "C", "B"],
}
report = run_coherence_analysis(raters)
print(report.verdict)

Consistency

from llm_classification_validator.consistency import RuleRegistry, run_consistency_check
from llm_classification_validator.models import RuleResult

registry = RuleRegistry()

@registry.rule("R-001", "Label is non-empty", severity="error")
def label_present(item: dict) -> list[RuleResult]:
    passed = bool(item.get("label"))
    return [RuleResult(
        rule_id="R-001", rule_name="Label is non-empty",
        category="structural", severity="error",
        passed=passed, item_id=item.get("id"),
        message="OK" if passed else "Label missing",
    )]

items = [{"id": "1", "label": "A"}, {"id": "2", "label": ""}]
report = run_consistency_check(items, registry)
print(report.verdict)

Convergent validity

from llm_classification_validator.convergent import run_convergent_analysis

predicted = ["A", "B", "A", "C"]
reference = ["A", "B", "B", "C"]
report = run_convergent_analysis(predicted, reference)
print(report.verdict)

Adversarial discrimination

from llm_classification_validator.adversarial import MinimalPair, AmbiguityCase, run_adversarial_analysis

def my_classifier(text: str) -> str:
    return "category_A"

pairs = [MinimalPair("p1", "input alpha", "input beta", "A", "B")]
ambiguity = [AmbiguityCase("a1", "ambiguous input", ["A", "B"])]
report = run_adversarial_analysis(my_classifier, pairs, ambiguity)

Stability

from llm_classification_validator.stability import (
    ParaphraseVariant, PerturbationVariant, ExpectedDirection,
    run_stability_analysis,
)

base_items = {"item1": "original text", "item2": "other text"}

def classifier(text: str) -> dict[str, str]:
    return {"category": "A", "subcategory": "A.1"}

paraphrases = [
    ParaphraseVariant("item1", "item1_p1", "formal", "the original text, formally"),
]
report = run_stability_analysis(base_items, classifier, paraphrases=paraphrases)

Full evaluation

Pass dimension runners (zero-argument callables returning DimensionReport) to the orchestrator:

from llm_classification_validator.runner import run_evaluation

def my_coherence_runner():
    return run_coherence_analysis(...)

def my_consistency_runner():
    return run_consistency_check(...)

report = run_evaluation(
    foundation=[my_coherence_runner, my_consistency_runner],
    advanced=[my_adversarial_runner, my_stability_runner],
    parallel_advanced=True,
)
print(report.overall_verdict)
print(report.summary)

See examples/aicm_to_faircam.py for a complete working example using real CSA AI Controls Matrix controls. The AICM-to-FAIR-CAM mappings are illustrative — replace with your own taxonomy pair.

Configuration

All thresholds, bootstrap parameters, sampling settings, and runner options are configurable via YAML or Python.

Copy eval_config.yaml and override what you need:

coherence:
  thresholds:
    - metric: mean_kappa
      target: 0.80
      minimum: 0.60
  bootstrap:
    iterations: 5000
    confidence: 0.95

adversarial:
  discrimination_target: 0.90

sampling:
  min_per_stratum: 5
  min_total: 30

from llm_classification_validator.config import EvalConfig

config = EvalConfig.from_yaml("eval_config.yaml")

See eval_config.yaml for all available options with defaults.

Statistical methods

All computations use the standard library only and following statistical methods:

• Cohen's kappa: two-rater categorical agreement
• Fleiss' kappa: multi-rater categorical agreement
• Jaccard similarity: set overlap
• Bootstrap confidence intervals: percentile method, configurable iterations and seed
• PASS / MARGINAL / FAIL verdicts: threshold-based with target and minimum levels

UI

The validation dashboard provides:

• Dimension radar chart comparing actual scores against target and minimum thresholds
• Configurable thresholds per dimension with live verdict recalculation
• Per-control issue view aggregating problems across all dimensions
• Adversarial detail panel showing minimal pair results

# Requires UI dependencies
pip install -e ".[ui]"

# Run the dashboard
PYTHONPATH=. python examples/run_ui.py

Tests

119 tests across 8 test files, all using standard library only.

pip install -e ".[dev]"
pytest

License

CC BY-NC-SA 4.0