A thesaurus on Alien Species for a faceted search
The Alien Species Thesaurus is a structured vocabulary constituting a public domain and distributed as a service by LifeWatch Italy. It is based on a glossary developed by the Mediterranean Thematic Centre in cooperation with the Collection Thematic Centre, and it provides the terminological resources that play a key role in developing the information architecture for the online LifeWatch portal and search platform about alien and invasive species. The Alien Species Thesaurus is deep and complex respect to other thesauri, implementing rich semantic interrelationships among core nodes like: control, impact, pathway of arrival, surveillance of alien species, and presents a cross-cutting nature across different ecosystems.
It is developed on the basis of already existing glossaries created within the framework of international initiatives aimed at the study of alien and invasive species. The terms (or concepts) are shared very broadly by the scientific community, and their definitions derive from guidelines prepared by relevant international organizations, and only in few occasions by peer reviewed papers. Certain terms (like the very broad alien species) have been repeatedly defined by different organisations, research centres, individual researchers, and the present thesaurus provides concept history tables to record changes in the vocabulary over time as the opinion changes.
The Thesaurus currently stores 319 terms with definitions limiting semantic ambiguity, and improving precision and recall due to uniformity of language, and 62 relationships. The idea is to guide all the searchers to use the same term for the same concept, so that search results will be as complete as possible.