[crypto5]

I think this is one of advertised advantages of deep learning: it will find useful and unobvious features in your data corpus without much effort from your side.

[kevinskii]

I think that works in theory, but in many real world cases it actually takes a human to map the data into a subset of salient features. It's not simply a matter of excluding irrelevant dimensions.

[msellout]

Actually, with deep learning the fact of success is leading the theory. We don't know why deep learning works as much as we know it does work.

Edit: in certain domains such as images and speech