Traditionally, ontologies are built, per domain, by ontology experts, after conducting lengthy interviews with people who are experts in that particular domain. For example, for a search function for a food website, chefs, caterers and students would be among those interviewed. This knowledge are formalised in specialist tools, such as Top Braid, or Protégé. These tools are highly flexible, however, require considerable expertise to use correctly. As a result, building ontologies is a slow and expensive process.
The Rapid Ontology Creation ROC+ is an ontology editor developed at Wageningen UR and offers an interactive method in which domain experts work together to create ontologies of their knowledge domain, supported by ontology experts. The ROC+ method consists of group sessions, in which domain experts come together and jointly discuss, document and agree upon relevant terms and relations in their knowledge domain. They are supported by the ROC+ software tool in which the actual ontologies are created. This web-based tool allows domain experts who are not ontology experts, to formalise their own knowledge and experience in a domain specific vocabulary, with inspiration from existing ontologies and document collections.
The method has been successfully applied in several projects such as ask-Valerie, which is a tool to facilitate knowledge transfer from scientists to agriculture and forestry practitioners and food technology portals. For the agricultural domain, AGROVOC and Eurovoc are existing ontologies as inputs for suggestions in ROC+ .
We also used the ROC+ method in the department of chemistry of Wageningen to enrich the vocabulary for reporting a chromatography experimental method. Five teams of two scientists covering different domain such as food chemistry, food process engineering participated in a ROC+ session and created an ontology consisting of 358 terms that support 2 types of relations: 77 synonyms using skos:altLab, 1 hierarchy using skos: narrower, skis:broader and 200 other types of relations using skos:related.
A ROC+ session includes completing 5 steps by a domain expert:
- entering of concepts into the ontology (e.g. mobile phase, run process etc)
- identifying synonyms (e.g., a user searching for a ‘mobile phase’ will also find results for “eluent” and etc.
- use existing ontologies to suggest per concept in the ontology other possibly relevant concepts (e.g. OM ontology)
- creating the hierarchy (e.g., skos) between the concepts. (e.g. RP is a type of chromatography technique)
- indicate relations between concepts (e.g., they can indicate that glutamate, glycine and pyrolysine, are all amino acid, or they can link the amino acid carnitine}, to lipid transport, where it is used
The result is a clear model of the knowledge within a given domain.