But that's not at all how "supervised learning" works. You would do something like have a thousand sanded pieces of wood and columns of attributes of the sandin

But that's not at all how "supervised learning" works. You would do something like have a thousand sanded pieces of wood and columns of attributes of the sanding parameters that were used, and have a human label the wood pieces that meet the spec. Then you solve for the parameters that were likely to generate those acceptable results. ML is brute force compared with the heuristics that human learning can apply. And ML never* gives you results that can be generalized with simple rules. * excepting some classes of expert systems