HCD.5:5.1 - Correct Calculation, Unsupported Cause

In a constructed pump case, flow remains 100 m³/h while measured power rises from 20 to 22.4 kW, so the calculated energy per unit volume rises by 12%. The person computes the ratio correctly but concludes that the controller change caused the increase. Current facts leave at least resistance, regulation efficiency, and measurement error as live explanations.

The target is not unit conversion or arithmetic. It is proposing competing explanations, stating a discriminating observation, and keeping the conclusion conditional. A selected Method set uses one worked explanation that makes the rival predictions visible, a coached discrimination attempt, and a later changed case in which the person must choose the next observation without the Method or answer supplied. Focused unit practice remains a surviving candidate only if a separate starting observation shows a unit error. Generic repetition of the original calculation is rejected because it does not address the target.

The selection account records the proposed reasoning mechanism, teacher feedback needed, safe stipulated data, changed-condition observation, and the limit that this exercise does not establish engineering capability or the causal effect of the Method.