LECTURE HUB
Lecture 11 - Regression to the mean
🚦 Status🌟 Mastered
🧠 Mastery🦅 Adept
📅 Last Review30 Nov 2025
🎯KEY TAKEAWAYS
- An extreme result is partly skill and partly luck. Next time the skill stays and the luck is redrawn, so the result moves toward the average. That is 🧩 Regression to the mean.
- It happens with no cause at all. Before explaining an improvement, ask what it would have done untouched.
- The predicted distance from average shrinks by the correlation: r of 0.6 turns two standard deviations into 1.2.
- Whoever intervenes right after the worst week will always look like a genius.
⚡QUICK JOTS
- same room, same radiator, same cardigan. Ezra has brought a cushion this term
- opened with a short video: a teacher shooting free throws. 📱 Regression to the mean with free throws
- best five shooters of round one get worse in round two. worst five get better. nobody coached anybody
- anything measured with luck in it will do this
- the worse the correlation between rounds, the harder the snap back
- praise seems to fail, shouting seems to work. both are the average pulling
- quiz on this next week
- the finger was discharged on Friday. I can hold a pen without thinking about it
☑️HOMEWORK
- Write 🧩 Regression to the mean with the carrier that had one bad month
- Revise for 📌 Statistics II - Quiz 1 - Regression to the mean
- Find a case at work where we rewarded or punished a result that was mostly luck
- Buy the course pack for the autumn