Term Dependence on the Semantic Web

A large amount of terms (classes and properties) have been published on the Semantic Web by various parties, to be shared for describing resources. Terms are defined based on other terms, and thus a directed dependence relation is formed. The study of term dependence is a foundation work and is important for many other tasks, such as ontology maintenance, integration, and distributed reasoning on the Web scale. In this paper, we analyze the complex network characteristics of the term dependence graph and the induced vocabulary dependence graph. The graphs analyzed in the experiments are constructed from a large data set that contains 1,278,233 terms in 3,039 vocabularies. The results characterize the current status of schemas on the Semantic Web in many aspects, including degree distributions, reachability, and connectivity.