Dependency Relations and Dependency Distance - a statistical view based on Treebank

The dependency relation is the most essential ingredient in a dependency-based theory of syntax. This paper presents some statistical findings on the dependency relation extracted from a Chinese dependency treebank. A sentence in the proposed treebank can easily be converted into a SSyntS graph in Meaning-Text Theory. The statistics on the dependency relation show that modifiers make up 55% of all dependencies and actants have a lower proportion of 45%. The paper demonstrates it is possible to extract from the treebank active and passive valence information of a word (or word class). The paper gives a formula to calculate the mean dependency distance (MDD) for a specific type of dependency relation in a language and obtains MDD of all dependency types in Chinese. These figures show that some dependencies tend to be much farther apart than others, and demonstrate that dependency distance tends to minimization and different dependency types have varying preference on the direction of dependency.