Constraint-based frameworks such as Optimality Theory (OT) have significantly altered phonologists' views on the nature of derivations and their role in linguistic theory. Earlier frameworks of generative phonology were characterized by a fairly complicated theory of derivations, involving lexical levels, the cycle, and intrinsic and extrinsic rule ordering, among other things. OT in its standard form, on the other hand, represents a minimalist theory of derivations, recognizing only a direct mapping from input to output. This volume addresses questions from many different points of view by a number of outstanding scholars: Is this minimal theory sufficiently well-equipped to deal with the empirical complications of natural language or do we need a larger 'derivational residue' in our theory? What are the relevant facts and how can we deal with them? Are there any reasons to think that an OT-based approach to derivations may even be more successful than its rule-based competitors? The book also features an introduction into the general issues involved and an extensive bibliography.