Engineering evidence is useful only when its label matches how it was produced. A person saying a task is complete, a connector finding a commit, and an independent check confirming a result provide different confidence. Keeping them distinct lets teams see what is known, where it came from, and what remains to be checked.
L0 Claimed: an actor reports what happened
Claimed evidence records a statement from a person or agent, such as "implementation complete" or "test run passed." It helps report progress and intent. By itself, it does not establish that a commit exists or a test ran. Keep the source visible so readers do not mistake an assertion for an independent observation.
L1 Observed: a trusted source reads an artifact
Observed evidence comes from a connector that reads an artifact directly, such as a repository event or check result. It establishes that the connected source reported that artifact; it does not necessarily show that the artifact satisfies a requirement. Retain its source and reference so a person can inspect the underlying event.
L3 Verified: an independent system checks an outcome
Verified evidence is produced when an independent system checks a defined outcome. A test can verify the cases represented by its assertions. The result is only as broad as the check: a passing test does not prove every behavior, deployment condition, or requirement. Record the check, its result, and the expectation it was meant to assess.
Preserve provenance and trust boundaries
- Store the source, time, and artifact reference with each evidence record.
- Do not let the actor being assessed promote its own claim into independent evidence.
- Keep observations and checks scoped to the workspace and system that produced them.
- Treat missing evidence as a question for review, not permission to mutate external systems.
Use evidence to guide review
Evidence levels do not replace engineering judgment. They help a team ask who reported this, which system observed it, what a check covered, and whether the result matches the requirement. When a work item lacks evidence its policy expects, make that gap visible and assign follow-up work.