Bias-variance tradeoff
----------------------

![](https://ars.els-cdn.com/content/image/1-s2.0-S0167739X1500223X-gr11.jpg)

> The bias variance trade-off is maybe not an ideal name, it should maybe have better been called interpolation/extrapolation trade-off. Anyway, the motivation for the name is that that when adding more parameters / complexity, you have

> - Less systematic error (bias) in your model (supposedly, because it is more flexible, I would argue it depends on what you call error / bias)
> - More variance in the estimation of the model parameters (because it is more flexible)

Florian Hartig at Cross Validated. [What is the difference between bias and residuals?](https://stats.stackexchange.com/users/48591/florian-hartig)