![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
How to choose the optimal value for K?
A.
Cross-validation can be used to determine a good value by using an independent dataset to validate the K values.
B.
Low values for K (like k=1 or k=2) can be noisy and subject to the effect of outliers.
C.
A large k value can reduce the overall noise so the value for 'k' can be as big as possible.
D.
Historically, the optimal K for most datasets has been between 3-10.