Sources and method

Know where the value came from — and where it stops.

An engineering number without its condition and provenance is difficult to review and dangerous to reuse. Howard is designed to return the value together with the information needed to judge whether it applies.

What travels with a result

The result is more than a number.

51 K rise over ambient

Quantity and unit: The measured quantity and the unit it is expressed in, never a bare figure.
Condition: The input condition the value was computed at, and the range over which it applies.
Reference: The formula, property source, table, or reviewed rule the result rests on.
As of: The version or as-of date of that reference, where the reference has one.
Assumptions: What was assumed to reach the value, and the limitations that follow from it.
Data status: Supported, limited, or no data — stated on the result, not inferred by the reader.

Significant figures follow the source and the model uncertainty. 51 K is more credible than 51.2719 K when correlations and boundary conditions dominate.

Source classes

Evidence appropriate to the question.

Howard may use reviewed manufacturer documentation, public agency data, published standards where licensed for the use, established engineering references, and versioned scientific property libraries.

What this page shows is the representative reference attached to an output. It does not expose the internal source inventory or the acquisition pipeline, because neither helps you judge whether a number applies to your product.

Refusal

No interpolation through silence.

What Howard will not do

Treat a property at room temperature as evidence at cold start.
Turn an unknown material pair into “probably compatible.”
Invent a fatigue life without an applicable curve.

When the evidence is insufficient, the useful answer is the missing input, the supplier question, or the test that would resolve it.

Coverage

Coverage is specific, not implied.

Coverage is published as a user-facing matrix by domain and condition, so the boundary is a fact you can read rather than something you discover mid-review.

Status	What it means for your question
Supported	The reviewed corpus covers this domain at this condition.
Limited	Covered in part; the result carries the limitation that narrows it.
No reviewed data	The corpus does not support the condition. Howard says so rather than estimating.
Outside scope	Not a question Howard answers, at any condition.

The matrix names domains and conditions. It does not publish raw table names, internal slugs, source ledger paths, or planned methods.

Corrections

Engineering evidence changes. Corrections remain visible.