| The Dual Mechanism Model (Pinker 1999, Clahsen 1999) posits two different cognitive mechanisms for morphologically complex word forms: decomposition of regulars into stems and affixes or exponents, and full-form storage for irregulars. Most of the research in this framework has been done on inflectional morphology. In this paper, we extend the model to derivational morphology. Our studies indicate a contrast between productive inflectional and derivational processes that is consistent with the Dual Mechanism Model as well as the Split Morphology Hypothesis. |