feature geometry

In NON-LINEAR PHONOLOGY, a model of the ways in which FEATURES are organized in phonological representations. Approaches to feature geometry look especially at the non-linear relationship between features, and at the way they can be grouped into a HIERARCHICAL array of functional CLASSES. Feature values are arrayed on separate TIERS (levels, planes, layers . . . ), where they may enter into non-linear relations with each other. At the same time, features are organized into hierarchical arrays, in which each CONSTITUENT functions as a single unit in phonological rules. Several models of feature theory have been proposed, such as ARTICULATOR-BASED FEATURE THEORY, CONSTRICTION theory, and UNDERSPECIFICATION