What's in a name: bias (intercept) In linear regression,  $y = w_0 + w_1x_1 + w_2x_2 + \cdots$. The intercept term is called 'bias'. Why is it called bias? And how is this different from the 'bias-variance' trade-off?

Bias is a general term and can have different meanings.

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*In statistics the term is used to describe a systematic error in an estimation method. It relates to splitting up error in accuracy and precision, and bias is the lack of precision.


*Bias is also used in relation to activation functions in neural networks. In that case it is the intercept as in your question. It is a term that changes how easily a particular node will 'activate' in response to the input values.

Why is it called bias?

You could say that the intercept is a term that makes the node biased to give a low/high value as response to certain input.

And how is this different from the 'bias-variance' trade-off?

Bias is a word used in different places.
In the list of uses of 'bias' above, the second use of bias has nothing to do with the bias in the bias-variance tradeoff which relates to the first use of bias.
