1 min readMohammad Shaker
[Bosanski] Half-Life Regression: The Algorithm Behind Amal's Adaptive Curriculum
[Prijevod] Amal's adaptive curriculum is powered by Half-Life Regression (HLR), a memory model where each learning item has a 'half-life.' The formula p(recall) ...
Learning Science
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[Prijevod] Amal's adaptive curriculum is powered by Half-Life Regression (HLR), a memory model where each learning item has a 'half-life.' The formula p(recall) ...
# Half-Life Regression: The Algorithm Behind Amal's Adaptive Curriculum
[Bosnian content]
## Half-Life Regression: The Algorithm Behind Amal's Adaptive Curriculum
Amal's adaptive curriculum is powered by Half-Life Regression (HLR), a memory model where each learning item has a "half-life" — the time for recall probability to drop to 50%. The formula p(recall) = 2^(-Δ/h) drives scheduling: items due for review are surfaced before the child forgets, while mastered items are spaced further apart. Combined with persona-based difficulty matching, this creates a truly personalized learning path for every child.
### The Math Behind the Memory
**Exponential Decay Model**
Memory doesn't fade linearly — it follows an exponential curve. After reviewing a concept:
- Right after review: 100% recall probability
- After h hours: 50% recall probability (by definition of half-life)
- After 2h hours: 25% recall probability
- After 4h hours: 6.25% recall probability
Amal schedules the next review when recall probability hits approximately 80% — the efficiency sweet spot.
**Worked Exampl
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