Bottom-Up vs. Top-down Ontologies

In this paper, we explore the relationship between language and ontology. We present the results of a manual linking exercise we performed between the CPA (Hanks 2004) and the DOLCE (Masolo et al. 2003) ontologies, with the goal of identifying the distinctions and similarities between the two systems from a cognitive and applied perspective. The motivation for our research stems from the differing nature of the two resources. The CPA ontology is a bottom-up system in which categories are identified through manual clustering of the noun fillers of argument positions of verbs gathered from large corpora. In contrast, DOLCE is a top-down ontology, where categories are not based on extensive linguistic evidence but are instead stipulated on formal grounds. We are interested in verifying whether the two methodologies (bottom-up and top-down) lead to differences in the resulting ontologies. The preliminary results reveal that the most general types in T-PAS can be mapped fairly well into DOLCE’s upper level. The experiment also shows that the bottom-up system is finer-grained and anthropocentric, in the sense that its categories reflect human experience, as conveyed through language use. On the other hand, the DOLCE taxonomy is ontologically more robust than the CPA hierarchy. Two substantial issues remain open: the mapping of the Abstract category, which is interpreted differently in the two ontologies, and the treatment of systematic polysemy.