HCD.18:5.2 - Contrasts that test what the specification can conclude

A deficient handout, M0, says that time spent doing a task runs from first touch to handoff. Its only worked example is uninterrupted. It offers some useful time-accounting content, but its central rule and example do not support the interruption distinction. S1 can locate a connected explanation–example repair even if a prepared reader independently returns all correct quantities.

A revised explanation, M1, distinguishes active intervals from start-to-handoff turnaround, separates the columns, gives the interrupted report result, and states how to sum person-time across people. This repairs the named subject relation. To become an adequate contrast for all of S1, the material-and-support arrangement must also supply the concurrent example, a criterion that accepts valid equivalents, and the specified reader/feedback evidence. “Better explanation” alone is not a complete six-coordinate result.

An adequate constructed contrast combines M1 with the concurrent worked comparison, the S1 criteria, and an available teacher question and retry. It shows what adequate content and support would contain. Until an appropriate reader actually uses that arrangement, explanatory and feedback adequacy remain evidence requirements, not observed successes.

The outside-use contrast is “this reader will retain the distinction independently next month.” It concerns a human retention claim. S1 returns outside use and points to HCD.13; it does not award the handout 0.

The practical change is visible before collecting new learner data: M0 can no longer pass on heading coverage and expert accuracy alone; the repaired material cannot acquire a learning claim merely by containing the right definitions; and the remaining observation is specific enough to undertake.