Dependency Grammar - Representing Dependencies

Representing Dependencies

There are various conventions that DGs employ to represent dependencies. The following schemata (in addition to the tree above and the trees further below) illustrate some of these conventions:

The representations in (a-d) are trees, whereby the specific conventions employed in each tree vary. Solid lines are dependency edges and lightly dotted lines are projection lines. The only difference between tree (a) and tree (b) is that tree (a) employs the category class to label the nodes whereas tree (b) employs the words themselves as the node labels. Tree (c) is a reduced tree insofar as the string of words below and projection lines are deemed unnecessary and are hence omitted. Tree (d) abstracts away from linear order and reflects just hierarchical order. The arrow arcs in (e) are an alternative convention used to show dependencies and are favored by Word Grammar The brackets in (f) are seldom used, but are nevertheless quite capable of reflecting the dependency hierarchy; dependents appear enclosed in more brackets than their heads. And finally, the indentations like those in (g) are another convention that is sometimes employed to indicate the hierarchy of words. Dependents are placed underneath their heads and indented. Like tree (d), the indentations in (g) abstract away from linear order.

The point to these conventions is that they are just that, namely conventions. They do not influence the basic commitment to dependency as the relation that is grouping syntactic units.