ABSTRACT
This chapter provides a detailed outline of the types of constraint interaction that have been proposed by phonologists working in Optimality Theory (OT), demonstrating that constraints can be organized and interact in a wide variety of ways. It addresses the issue of the content or formalization of constraints, including functional grounding. OT was conceived as a generative theory of constraint interaction, rather than a theory of constraints or representations or processes. The heart of OT is summarized in the Richness of the Base Hypothesis, which states that all linguistic variation stems from the interaction of universal violable constraints rather than language-specific rules and restrictions on the lexicon. Constraint interaction is the source of cross-linguistic variation. The basic form of constraint interaction is considered to be ranking in a hierarchy. OT constraints are expected to be grounded either typologically or functionally, rather than just stipulated or descriptively convenient or a rephrasing of a generalization or rule.
