# Causality, part 1 - Bernhard Schölkopf - MLSS 2020, Tübingen - YouTube

source
https://www.youtube.com/watch?v=btmJtThWmhA&feature=youtu.be

## Background and Motivation

Consider a dataset of temperature $$t$$ vs altitude $$a$$. We typically see that the larger the altitude, the lower the temperature. How do we know if this is a causal effect?

1. Intervention: we can raise the city, and find that the temperature changes
2. Hypothetical intervention: expect that $$t$$ changes, since we can think of a physical mechanism $$p(t|a)$$ that is independent of $$p(a)$$. We expect that $$p(t|a)$$ is invariant across different countries in similar climate zone.

A “structural” relation not only explains the observed data; it captures a structure connecting the variables.

An equation becomes structural by virtue of invariance to a domain of modifications.