Choose an observation by the work it can change

Ask what you would expect to observe under each retained account. A useful question, small work sample or permitted observation makes those predictions differ at a point relevant to the receiving result. An assurance such as “I understand” fits both calculation accounts too easily. Repeating a person’s own words may test recall while leaving their use of those words unknown. Prefer a return that exercises the disputed meaning or exposes the proposed operation.

Here the collaborator is available, showing one row is quick, and substantial calculation remains. Request: “For case 17, show the expression and pass/fail meaning you will return. Which source will your next check use?” The expression tests current use of the convention; the source answer reports the intended continuation. Their evidence is different: one performs a small calculation, while the other says what is planned. A.15.9 helps bound that requested contribution and the reliance placed on it.

Compare the question with explaining the convention directly, specifying the source contribution explicitly, completing the remaining calculation yourself, or proceeding on the current evidence. MMP.8.SD models the information available at each choice and the continuation an observation enables. A small qualitative branch comparison is enough here: a wrong formula leads to explanation and a new application; a correct formula avoids needless reteaching; a copied-table plan changes the requested source contribution. C.11.DUA asks whether that difference warrants the question’s whole burden. The stipulated quick return and substantial dependent work make this probe useful; they are not measured savings.

If only one short calculation remains, requesting its complete, checkable return may finish the work directly. If an explicit explanation and division are cheaper and adequate under all remaining accounts, use them. When the partner is unavailable or the distinction cannot be observed in time, choose a supported continuation under the unresolved alternatives or state the missing condition. The example’s two questions are not a form that every collaboration must complete.