Learning has three elements: it involves retention, transfer and change. Learning must be durable (it should be long-lasting), flexible (it should be applicable in new contexts) and liminal (it stands at the threshold of knowing and not knowing).
Cognitive development happens incrementally; the only way for a teacher to find out whether a student’s understanding of the world has changed is to wait. If we accept that learning is the retention and transfer of knowledge over time, we must also accept that learning cannot easily be observed in a single lesson. We must look at what students can do elsewhere and later.
Therefore, it follows that to know whether something has been learned, we should ask ourselves three questions: