LECTURE HUB
Lecture 18 - Causal questions with observational data
🚦 Status🟠 Studying
🧠 Mastery🐥 Apprentice
📅 Last Review8 Dec 2025
🎯KEY TAKEAWAYS
- Without randomisation, a causal claim rests on a diagram of what causes what, drawn from knowledge of the world and not from the data.
- Adjust for things that cause both. Leave alone things that are caused by both.
- A model can fit beautifully and be about the wrong thing. Fit is not truth.
- Show the work to someone who uses statistics for a living before the person who marks it.
Read with
- 🎓 Lecture 13 - Confounding and what regression cannot tell you
- 🔤 Confounder
- 🧩 Confounding
- 00. Statistical Rethinking Hub
- Port Authority open vessel-delay data
⚡QUICK JOTS
- context: Hana Kobayashi rang at four. my best variable in the project is mostly the season. tonight's lecture is that mistake, as a topic
- observational data = nobody randomised anything. which is nearly all data
- draw the arrows FIRST. what causes what. then decide what to adjust for
- adjust for common causes. do NOT adjust for common effects, it invents a link
- natural experiments: something outside changed one group and not the other
- Hale: the data cannot tell you the arrows. you bring the arrows
- showed him the refit at the break. he nodded and asked what else changes with the season. there is always a smaller question
☑️HOMEWORK
- Refit the project model with the season in it and rewrite the findings
- Draw the arrows for the port delay data on one page and put it in the appendix
- Thank Hana properly. Coffee is not enough
- Submit 📌 Statistics II - Project - What predicts vessel delay at Greywater on the 25th
- Read ahead for the last session