LEARNINGCORE
Multi-Armed Bandit
Balance pulling the best-known lever against testing new ones. Regret is the score.
How it works
- Each pull teaches and earns — explore or exploit, every round.
- Regret (vs the best lever in hindsight) is the scoreboard.
- Optimism under uncertainty: try what could plausibly be best.
Use → Trials, dosing, ad creative. Run small experiments, then exploit.
Watch out → Declaring a winner after ten pulls.
Try it → A/B/C test with 10% exploration for a month.
REDCAPE jobs → Act · Explore
Free sources → Wikipedia: Multi-armed bandit (CC BY-SA) • Coursera M11 (Learning)
Attach to a lattice — combines with
Different families, shared jobs. Disagreement between them is where insight lives.
DYNAMICS
Markov Chain
Next state depends only on now. Run it forward to get the long-run mix.
SHARED JOBS: ACT · EXPLORE
DIFFUSIONSIR Contagion
Susceptible–Infected–Recovered with an R0 tipping point. Same math for flu and pop-star fever.
SHARED JOBS: ACT · EXPLORE
GROWTHCapital Share (r > g)
When returns on capital outrun growth, wealth concentrates without any villain.
SHARED JOB: ACT
More in Learning
Replicator Dynamics (Fisher)
Winning strategies reproduce faster; adaptation speed rises with variation.
Rugged Landscapes (NK)
Interacting parts create many local peaks; hill-climbers get stuck, diverse searchers find higher ground.
Diversity Prediction Theorem
Crowd error equals average error minus diversity. Diverse models beat the lone genius.