HCD.23:5.1 - Agreement about a number conceals a different model

In this constructed case, two learners compare a release plan. The supplied rule requires two active specialist-hours per change and one further active hour for every batch of at most four changes. A 24-hour allowance is available. Both initially say ten changes fit. Learner A calculates twenty hours and omits batching; learner B calculates twenty plus three batch hours.

Their initial agreement conceals a consequential difference. B explains why ten changes require three batches. A reconstructs the count as four, four and two, and computes 23 hours. A then asks whether the overhead is active work or merely elapsed waiting. The supplied rule explicitly says active work; if it did not, that unresolved quantity would need clarification before comparison.

The next personal task lowers the allowance to 22 hours. An answer of eleven changes from dividing by two fails the declared rule. Nine changes need eighteen plus three, or 21 hours; ten still need 23. The learner must change the proposed action and explain the batch count. If B supplies nine before A attempts it, A’s later correct answer is assisted reconstruction. Preserve that result and use a fresh case if independent adaptation is the receiving question.

Now change the subject rule: setup is required once for the entire run. The previous three-overhead calculation no longer applies. Both learners must return to the changed rule instead of treating the learned arithmetic as a universal template. The comparison teaches attention to the condition governing the operation.