in deep learning you don't have to do feature selection, this is automated by the deep learning algorithm by looking at the patterns of the data. we just feed it in and see the output classification. Talking about automation, this is a time saver for human being isn't it? The point why computer is really helpful to us is the fact that it could automate task. Now, do we need to understand how the machine do it? I think this is just a matter of trust or fear from humanity to machine. We don't need to understand anything, but sometimes what it matters is solving the problem. Like a doctor giving the medicine to a patient, granted he or she will have the understanding of how the medicine works into human body. This understanding however is 'limited', the doctor kind of 'trust' the work of the people who created those medicine that it will do no harm to the body. But the truth of the matter is it does not work always that way. There is a degree of 'blac