Mapping definitions

The DASISH metadata catalogue can be browsed by exploring facets. A facet, in this case, could be regarded as 'a way of looking at metadata elements'. 'A way' since there is always some interpretation: the original definition of a particular metadata element is regarded to have, to some extend, the same meaning as the definition of the facet it is mapped onto. Sometimes, this mapping is quite straightforward, like in the case of the Dublin Core element 'creator' for example. This element is mapped onto the catalogue's 'Creator' facet. By this mapping the Dublin Core definition is taken to be not contradictory to the catalogue's own 'Creator' definition.

Not in all cases the interpretation is straightforward. Because the metadata to be mapped conforms to definitions created by different organisations, it is not possible to include every metadata element encountered as a facet. Metadata might for example include the 'PublicationDate' element, while this element is not a facet in the catalogue. Consequently, a metadata element will not be mapped, or it will be mapped onto a facet defined in terms different from those in the original definition of the element. 'PublicationDate' could for example be mapped onto the 'CreationDate' facet.

In the catalogue, metadata elements with substantially different definitions need to be represented by one and the same facet. This calls for decisions to be taken. For example that an 'actor' element in some metadata definition can indeed be interpreted, viewed through, the 'contributor' facet. In exactly this sense the metadata catalogue is more than just an compilation of metadata. Careful interpretation when defining mapping the metadata to facets results in a unified way of access to metadata gathered from various providers.

Describing the metadata catalogue therefore not only means 'to describe facets'. It also means 'to describe the considerations involved in creating a mapping of metadata elements to the facets.