* Tags:: Book (still not read)
* Author:: [[aston-zhang|Aston Zhang]], [[zach-c.-lipton|Zach C]], [[mu-li|Mu Li]], [[alex-j.-smola|Alex J]] (Amazon Data Scientists)
* Link:: [Dive into Deep Learning — Dive into Deep Learning 0.17.2 documentation (d2l.ai)](https://d2l.ai/index.html)
* Source date:: [[2021-01-01]]
* Finished date:: [[2021-01-06]]
## 4.9 Environment and Distribution Drift
[[Covariate shift|Covariate shift]]: That p(x|y) remains constant is an assumption we make, and we do so in circumstances where we believe that x causes y.
[[Label shift|Label Shift]]: That p(y|x) remains constant is an assumption we make in cases where we believe that y causes x (disease -> symptoms).
[[Model drifting|Model Drifting]]: We may also have a third case, [[Concept drift|Concept drift]], where the very definition of "y" may change. The only thing we can do is exploit knowledge of those variations being very gradual in time, space...