Skills fade fast after a single training day — without reinforcement, most new knowledge decays within weeks. A single post-course test only proves what someone knew at four o'clock on the day.
The first follow-up at weeks 2–3 lands just as that decay sets in. Retrieving the knowledge at that point interrupts the forgetting and strengthens it. The second, at weeks 6–8, arrives once new routines have settled on shift — and tests deeper, applied understanding rather than simple recall.
Research in nurses and other health professionals suggests spaced testing leads to significantly better long-term retention and safer decision-making than a single post-course test.
