Complicate Locally, Simplify Globally: Starting with Complex Primitives Pays Off

In setting up a formal system to specify a grammar formalism, the conventional (mathematical) wisdom is to start with primitives (basic primitive structures) as simple as possible and then to introduce various operations for constructing more complex structures. An alternate approach is to start with more complex primitives, which directly capture some crucial linguistic properties and then to introduce some universal operations for composing these complex structures. These two approaches provide different domains of locality, i.e., the domains over which various types of linguistic dependencies can be specified. This latter approach, characterized as "complicate locally, simplify globally (CLSG)", pushes non-local dependencies to become local, i.e., they arise in the basic primitive structures to start with. I will explore the CLSG approach in the context of some mathematical, linguistic, computational, statistical, and psycholinguistic properties, all these with possible relevance to the cognitive architecture for language. I will describe these results in an introductory manner.