OCR: Evaluation and operations

Covers fixtures, retrieval and answer metrics, monitoring, freshness checks, debugging, and recovery for OCR. This reference fixes the adoption boundary, failure behavior, and observable evidence while leaving environment-specific limits configurable.

Package status: reference context ready for human review. The contract and test scenarios are complete, but no claim is made that an adopting implementation has passed them.

Decision

For OCR, adopt a versioned source, transformation, index, and access-control lineage. Treat the block as a release and regression contract built from representative positive, boundary, denial, failure, and recovery cases. This package is a reference contract: the adopting team must choose numeric limits, providers, jurisdictions, and operational owners from evidence in its own environment.

Scope

• The OCR actors, inputs, outputs, states, policy or schema versions, and externally visible outcomes described by this testing block.
• Primary and alternate interfaces, background work, caches, integrations, support paths, and evidence that can exercise the same boundary.
• Adoption-specific configuration, rollout, recovery, and verification responsibilities needed to apply the reference safely.

Outside this block

• Choosing a universal vendor, framework, jurisdiction, numeric threshold, retention period, or service-level objective for every adopter.
• Claiming that packaged scenarios have run against a downstream implementation or that this reference grants legal, security, or accessibility certification.

Contract

• Preserve source identifier, version, location, access scope, parser, normalization, chunk, embedding, and index versions for every retrievable unit.
• Apply access filters before results, snippets, counts, caches, and model context are exposed; post-filtering alone is not sufficient.
• Quarantine parsing or transformation failures and prevent a partial artifact from silently replacing the last complete version.
• Evaluate retrieval and grounded-answer behavior on versioned representative cases, including conflicts, absence, staleness, and adversarial text.
• Record fixture version, environment, configuration, observed result, and evidence location for every decision-bearing run.
• Separate product failure, dependency failure, test-infrastructure failure, and inconclusive evidence in reports.
• Evaluate OCR by document class, language, layout, image quality, table structure, and field importance rather than one character average.
• Keep page images, text regions, confidence, engine version, and human corrections linked so low-confidence content can be excluded or reviewed.

Implementation guidance

• Build the smallest deterministic fixture set that spans risk classes, then add production-derived cases only after privacy-safe review.
• Model OCR inputs, outputs, actors, states, invariants, side effects, and evidence before selecting framework or vendor details.
• Store the applicable OCR contract or policy version with material state so migrations, replay, and support decisions remain attributable.
• Introduce the path behind controlled rollout, compare expected and observed outcomes, and keep a tested recovery route until adoption evidence is complete.

Failure handling and safeguards

• If provenance, access scope, or required content is missing, exclude the unit and expose a diagnosable coverage gap instead of fabricating completeness.
• Invalid or contradictory OCR state is rejected or quarantined; the implementation never guesses a value that broadens authority or duplicates an effect.
• Retries are bounded and use durable identity; after exhaustion, work reaches an inspectable terminal state with an accountable owner.

Verification and operations

• Run the suite twice from a clean state and confirm that ordering, retries, and parallel execution do not change the verdict.
• Monitor OCR success, denial, validation failure, dependency failure, retry exhaustion, and recovery by contract version without sensitive payload dimensions.
• Re-run paired positive and negative fixtures after policy, schema, dependency, migration, or boundary changes and preserve the resulting evidence.

Adoption assumptions

• Names and values in the example are a concrete fixture, not universal defaults; adopters replace them through documented evidence and ownership.
• The adopting system can provide authenticated identity, durable operation or record versions, bounded telemetry, and a controlled path for change.

The executable-looking examples in this package are fixtures and acceptance contracts. Run the collection validator to check structure and metadata, then translate and execute the scenarios in the target repository before recording implementation evidence.

References

• NIST AI 600-1, Generative AI Profile (applies as of 2026-09-08)