I don't think he was saying that the computer itself decides what the best setting is, but rather that it tests a range of options (given by the user) and prese

I don't think he was saying that the computer itself decides what the best setting is, but rather that it tests a range of options (given by the user) and presents the results in aggregate (using reductions specified by the user) so that the user can more easily make the decision. This specification of the ranges also solves the problem of optimizing multiple parameters simultaneously — people usually begin with hunches about what the optima are, which significantly limits the number of possibilities the system will have to test.