# Desirable Difficulty 三项技术 — retrieval verified

User correctly identified and described all three techniques in their own words (partly in English):

1. **Retrieval Practice**: "retrieve information from remain storage, strength practice" — pull from brain, don't re-read
2. **Spacing**: "increase forget, challenge your brain" — counterintuitive: deliberate forgetting makes retrieval harder and more effective
3. **Interleaving**: "mixed practice, give more pressure on situation choose" — forces choosing the right approach per situation, not auto-pilot

User self-generated English phrasing ("increase forget", "pressure on situation choose") indicates deeper processing than parroting Chinese terms. The English switch itself is an interleaving demonstration.

All three techniques have been actively used across Lessons 0001-0005 — user can now name what they've been experiencing.