# Reviewing a value calculation or implementation

A useful review connects a claim to a named method, inspectable inputs, and reproducible behavior. Start by identifying exactly which claim is being evaluated.

## Identify the review boundary

Is the review about an explanation, a valuation method, a calculation engine, a data adapter, or an operating service? Each needs different evidence. Success at one boundary does not establish success at every other boundary.

Record the source document and version. If you are reviewing software, record the release identifier and environment. Separate your observation from an interpretation or proposed change.

## Inspect the inputs

| Evidence | Question to answer |
| --- | --- |
| Units and quote direction | What does one numeric input represent? |
| Method revision | Were both values produced on a consistent reference scale? |
| Provenance | Where did each observation originate? |
| Observation time | When was the value observed, rather than downloaded? |
| Freshness policy | What age and future-time checks apply? |
| Numeric policy | Where is rounding applied, to what scale, and with which rule? |

The [oracle reference](?page=seed-content/oracle-system/index) provides context for external observations.

## Reproduce the result

Keep the original inputs and run the same method. Compare exact calculations before comparing rounded displays. Include expected and actual results in the record. A discrepancy should identify the smallest example that exposes the difference.

The [learning lab](?page=lab) exports an arithmetic evidence record for synthetic inputs. It is useful for investigating rounding or input sensitivity; it does not validate a real-world data provider.

## Challenge a boundary condition

Try missing values, zero or malformed reference inputs, rounding ties, and incompatible units. Snapshot-based code should also reject stale and future observations under its declared policy. Report which cases were tested and which were not.

## Report an actionable finding

Describe the observed behavior, the relevant requirement or assumption, the impact, and a proposed next step. Include alternative explanations and questions that remain unresolved. Avoid giving a general conformance label to a review that covered only one small calculation.

Prepare a [review brief](?page=contribute). For changes to standard behavior or governance, consult the [RFC process](?page=seed-content/rfc-proposals/index) and [audit guidance](?page=seed-content/audit-compliance/index).