2AA}{f} \right)\)`, reducing bias.
- Models that are too simple have high bias.

.hi-purple[Variance:] The amount `\(\hat{\color{#20B2AA}{f}}\)` would change with a different .hi-slate[training sample]
- If new .hi-slate[training sets] drastically change `\(\hat{\color{#20B2AA}{f}}\)`, then we have a lot of uncertainty about `\(\color{#20B2AA}{f}\)`.
- Models that are too flexible have high variance.

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# Model accuracy
## The bias-variance tradeoff

The expected value of the .hi-pink[test MSE] can be wri