Ontologier i kunskapsorganisation Vägen från tesaur till den semantiska webben
This thesis aims to analyse ontology, primarily as the word is used in the context of the Semantic Web. One of the main questions is how ontologies relate to classification and thesauri, two concepts well known within Library and Information Science. The vision of the Semantic Web, a more intelligent addition to the current World Wide Web, has raised the question of how to deal with information scattered over a multitude of locations, stored in different formats, written in different languages et cetera. This issue is in many ways similar to the classical problems encountered in library science: how to classify and categorise large amounts of information. The use of ontologies is one of the main steps leading to the Semantic Web, as well as a tool which can be used in other areas of information organisation and management. The main use of an ontology is to provide a standardised way of describing the area of interest. The results of the study show that there are several similarities between ontologies, classification and thesauri, but also that ontologies add some aspects compared to the others. The main differences are that ontologies require that relationships are defined formally in order to avoid ambiguities, and that they can handle concepts in addition to terms. This makes ontologies more powerful, especially when using computer based systems. Utilising an ontology makes it possible for a computer to draw conclusions based on the data provided, something that is not possible when using a thesaurus.