Abstract
Through the spread of ontological engineering, many technologies and software tools for ontology construction have been developed. By using them, many ontologies have been constructed in various domains. On these backgrounds, we have been developing an ontology engineering environment "Hozo" and using the tool to construct a lot of ontologies in various domains such as medical science, bioinformatics, nano-technology, education, environmental engineering and so on. Through these practical experiences, we have noticed many issues concerning ontology construction and have solved them by enhancing the ontological theories and technical functions of Hozo. The number of items of improvements amounts to 72 in both theoretical and practical issues. This paper focuses on the practical issues and presents the improved functions of Hozo. They are grouped into three kinds: 1) issues in the ontology design/construction phase, 2) ones in the ontology utilization phase, and 3) ones in the ontology refinement phase. We discuss requirements to solve the practical issues in each phase and demonstrate improved functions of Hozo. Then, we consider how those functions have been useful for ontology construction through actual uses in six ontology development projects and evaluation experiment of usability of Hozo. Through these extensions, usability and reliability of Hozo has been improved.
