Quantitative metadata on e-government ontologies in the oeGov repository

Ontologies play an important role in Semantic Web (SW) applications. However, it is costly and time consuming to build new ontologies de novo. One solution is to reuse existing ontologies when developing SW applications. To this end, TopGuadrant has launched the oeGov ontology repository to store and share a number of e-government ontologies of the US government. However, at present, the oeGov repository does not provide quantitative metadata on these ontologies to give an idea of their scales or sizes. This study uses online ontology documentation tools to iteratively gather quantitative metadata including the number of classes, properties and instances of the e-government ontologies in the oeGov repository. The analysis of these metadata revealed that only the 3 top level ontologies in the oeGov architecture are complete ontologies; the majority of the constituents of the oeGov are instances or datasets of the top level ontologies. These quantitative metadata further revealed that the bigger top level ontology in the oeGov is the government ontology (gov) with 151 classes, 72 properties and 24 instances, follows by the geopolitical ontology (geopolitical) with 11 classes, 101 properties and 312 instances. This metadata information may be useful for understanding the basic characteristics of these ontologies for their reuse in the e-government community.