Title: YAMATO:Yet Another More Advanced Top-level Ontology Riichiro Mizoguchi ISIR, Osaka University http://www.ei.sanken.osaka-u.ac.jp/ Abstract Upper ontology plays a critical role in ontology development by providing developers with a guideline of how to view the target domain. Although some upper ontologies such as DOLCE, BFO, GFO, SUMO, CYC, etc. are already developed and extensively used, a careful examination of them reveals some room for improvement in a couple of respects. This paper discusses YAMATO : Yet Another More Advanced Top-level Ontology which has been developed intended to cover three features in Quality description, informational objects and Processes/Events, respectively, in a better way than existing ontologies. In my talk, I will discuss fundamental characteristics of YAMATO as well as our role theory. Role theory explains how to deal with roles such as wife/husband, president, teacher, murderer, cause/effect, symptom, etc. which exist in the real world in a different way from ordinary types such as human, family, school, etc. A convincing method for property description is necessary for interoperability of all kinds of data. Without knowing how processes are different from events, no one can build a good model of dynamism of the real world. I hope my talk will give audience in-depth understanding about the utility of YAMATO and my role theory.