DIFFUSIONSTARTER
Broadcast Model
One source reaches a fixed pool at a steady rate: fast early, then fading returns — the r-shaped curve.
How it works
- Each period the source converts a fixed share of those not yet reached.
- The unreached pool shrinks, so new adoptions fall every period.
- Cumulative adoption bends concave — no takeoff, no tipping.
Use → Ads, press releases, mandated rollouts. If growth is S-shaped instead, word of mouth is doing the work.
Watch out → Expecting an S-curve takeoff from a campaign with no peer-to-peer spread.
Try it → Plot weekly signups after a one-off announcement; check if each week's gain shrinks by a steady ratio.
REDCAPE jobs → Predict · Communicate
Free sources → Coursera M4 (Diffusion)
Attach to a lattice — combines with
Different families, shared jobs. Disagreement between them is where insight lives.
LINEAR & NONLINEAR
Categorical & Threshold Models
Buckets and cutoffs turn messy attributes into testable if-then rules.
SHARED JOBS: PREDICT · COMMUNICATE
LEARNINGDiversity Prediction Theorem
Crowd error equals average error minus diversity. Diverse models beat the lone genius.
SHARED JOBS: PREDICT · COMMUNICATE
DISTRIBUTIONSEntropy & Uncertainty
Entropy scores surprise: equilibrium, cyclic, random and complex outcomes sit at different levels of uncertainty.
SHARED JOBS: COMMUNICATE · PREDICT