Lesson 5.10: Ontologies for integration in Integrated Assessment

Icône de l'outil pédagogique Authors

Sander Janssen, Ioannis N. Athanasiadis

Icône de l'outil pédagogique Our definition of ontology
The term ontology originates from philosophy, originally coined by classical philosophers Plato and Aristotle (Aristotle, 336-332 BC) in the study of types of being and their relationships (metaphysics). An ontology in computer science is considered as a specification of a conceptualization (Gruber, 1993), where a conceptualization is ‘an abstract, simplified view of the world e.g. systems under study that we wish to represent for some purpose’ (Gruber, 1993). Such a formalization could be expressed in a machine readable format, i.e. as the Web Ontology Language (McGuinness and van Harmelen, 2004). An ontology consists of a finite list of concepts and the relationships between these concepts (Antoniou and van Harmelen, 2004). Figure 1 gives a simple example of an ontology for a car by showing concepts (e.g. Car, Wheel, Cabrio and Jeep) and relationships (e.g. hasWheels and is-a). The car-ontology shows us that a car has wheels and that both cabrio and jeep are cars, that consequently also have wheels.

Figure 1. An ontology for a car with kinds of a car (a jeep and a cabrio) and a relationship between concepts car and wheels through the hasWheels relationship.

Icône de l'outil pédagogique Ontology and integrated assessment research
Integrated assessment research is characterised by, among others, its interdisciplinarity and its stakeholder interaction. Thus, integration between disciplines and between researchers and stakeholders is often an important objective of integrated assessments. In our experience, in this integration different types of misunderstandings around the meaning of concepts can occur:
  • as the same concepts might be used for different meanings, for example area in a model and area in the database,
  • as different concepts might be use, which have the same meaning, for example a internal user and an integrative modeller,
  • as concepts might be used with an ambiguous meaning, for example scenario (Schoemaker, 1993),
  • as relationships between concepts might be understood in a different way, for example between the different spatial scales and administrative regions.

To avoid these misunderstandings and to achieve a common jargon between researchers common ontologies can be used. A common ontology, i.e. ontology which is shared by all researchers participating in integration, serves as a knowledge-level specification of the joint conceptualization of the participating researchers. Each researcher must adhere to the semantics of the concepts in the common ontology, including restrictions on the concepts and relationships between the concepts.

Icône de l'outil pédagogique Example of ontology use from agricultural domain
In the SEAMLESS integrated assessment project different models, data sources and indicators are integrated into one operational tool. This integration requires particularly achieving a common understanding of the terms used in this tool by researchers from different disciplines with a dissimilar experience and education. In Figure 2 a very small part of the SEAMLESS ontology is provided as an example. This example shows the relationships between concepts products and crops as used by some of the models in the SEAMLESS project.

Figure 2. Concepts crop and product, their mutual relationships (e.g. OfCrop and Produces) and their properties (e.g. Name, Producttype and HarvestIndex).

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