Does the graph of k always follow this shape?


#1

Question

In the context of this lesson, does the graph of k for any dataset follow this shape?

Answer

In general, yes, any dataset should follow a similar shape as the one shown, although it may appear slightly different.

The general trend that is shown in a k vs validation accuracy graph will be as follows.

For small values of k, the accuracy will be low, because the model will overfit the data.

As k increases, accuracy will also increase, until eventually reaching a sort of “hump” shape, where the best value of k will be between. In this particular graph, this happens around the value k=74, where the validation accuracy is highest.

After this “hump”, the accuracy will continue to drop, as k increases further, and underfitting occurs due to high k values.