Chapter 4 aims at evaluating the classical parameters of GB Theory from today’s point of view. The first parameters discussed are those concerning S′-deletion, Subjacency, long distance anaphora, the Projection Principle, and nominative Case assignment, which are shown either to refer to obsolete theoretical concepts or to be reducible to other, more basic theories. Then, the discussion turns to those parameters whose epistemological status is still being upheld in Minimalism, that is, those concerning null subject, V-to-T and V-to-C movement, polysynthesis, and overt vs. covert wh-movement, by looking at their respective minimalist reformulations. What emerges from this investigation is that, strikingly, the only traditional parameters here reviewed which still enjoy an independent theoretical status are those which in Chapter 2 have been labeled as Spellout parameters. Moreover, the overt vs. covert wh-movement parameter could well be an exception in this sense. In fact, assuming Richards N. (2010) or an equivalent PF-based account is on the right track, wh-movement pertains to the A-P interface.