Quote:
Originally Posted by magdon
Apologies for the confusion.
Noisy target and deterministic target refer to a specific target value (for example at a specific point x). So you have a data point (x,y).
If y=f(x), we say that y is a deterministic target and f is a deterministic target function.
If for the same value of x you may observe different values of y (the example in the book: several people may have the same income but some may default on credit debt and some may not), then we say that y is a noisy target  its value is not deterministically determined given x. The way we model this situation is using a target distribution P[yx]. So P[yx] is the distribution of the (noisy) target, and we call it the target distribution.
Hope this helps.

So y here serves as a (random) variable?