Honest Error-Metric Scope - Forecast Error Metrics, Step by Step

The final lesson states the boundary: these are deterministic held-out error metrics.

highlighted = computed this step

Held-Out Only

The metrics score these held-out rows only.

\text{held-out arithmetic only}

Not Future Accuracy

Lower error on these rows does not prove future accuracy.

\text{future accuracy remains outside scope}

Not Causal Proof

The what-if comparison is arithmetic, not causal proof of a better process.

\text{comparison is not causality}

Honesty Note

This is deterministic held-out forecast error arithmetic only. It does not prove future accuracy, forecast stability, causal improvement, or model quality outside the pinned rows.

\text{deterministic forecast error arithmetic only}