NSTD.8:10 - Rationale

Different learning aims require different combinations of explanation, examples, attempts, feedback and later returns. Keeping the subject structure accessible permits a teaching route to vary those combinations without making the lesson sequence the only account of the subject.

A modular source corpus can support lookup and a first introduction while still leaving later selection unpractised. When learners must choose among similar methods without a topic label, the learning route needs those contrasts and selection tasks. When later retrieval matters, it needs an appropriate delay and return. The source organization remains available; whether the learning order should follow it depends on the task and the support already available.