An Iscape is dynamic in that the information it leads to is not a single precomputed data item but rather a collection of related datasets that is generated at runtime. It can therefore be considered an information request that can be expressed as a combination of keyword, attribute, and content based search. RDF uses XML as its underlying syntactic model. The attribute search part of an Iscape is constructed by describing involved entities taken from different domain ontologies. In order to eliminate ambiguity, information beyond the names of the correlated terms is required.
Ontologies provide such additional information.
Ontologies are used to describe not only the datasets we are interested in, but also the retrieved datasets, which are of a heterogeneous nature. One set of query may contain maps, real videos and Word Perfect documents. A classification of all possible datasets not only supports this behaviour but has also additional advantages. Multiple ontologies that are topic specific will be created to describe the whole model.