ANONYMOUS wrote: There is not a clear answer, since as I say: In a system with no known model where we are not able to assume anything about the structure of the system, they become basically equivalent. This information is covered in the lectures. In general you are expected to have a sufficient understanding of the logic and properties of these techniques that you should be able to assess a novel situation and determine for yourself the merits or disadvantages to each approach (or, indeed, when they are basically equivalent).