Lesson 2: Noise, sample size and fair comparisons
22 min read·13 Oct 2026
Module 10 · Lesson 2 · About 50 minutes · Needs: Module 1 Lesson 4 (the Wilson interval, the noise floor), Module 4 Lessons 2 and 4 (the control prompt, the boundary rule, discordant tickets)
The situation
It is Monday 3 August 2026, week 10, and shadow mode starts today. Two triage versions compete: v1, Module 4's control prompt, and v2, the same prompt plus the boundary rule written for T-1004, Yuki Sato's refund request 20 days into an annual plan.
Your rehearsal on the local instrument model gives v1 12 of 24 and v2 9. Maya asks: "Is v2 worse, or is that luck?" This lesson builds the answer: an interval on every score, the noise floor, the number of tickets a difference needs, error analysis, and a paired comparison. T-1004 is the running example.