The Rijksdienst voor Oudheidkundig Bodemonderzoek (National Service for Archaeology, Cultural Landscape and Built Heritage or ROB) is currently developing the Nationale Referentiecollectie (National Reference Collection). This collection contains archaelogical objects that are representative for a limited type of objects. Such collections are also called type collections.
As a pilot, the ROB has developed two type collections: a glass collection that consists of 320 objects with descriptions, photos, drawings and references to secundary literature, and the Corpus Middeleeuws Aardewerk (Medieval Ceramics Corpus), which comprises approximately 450 descriptions and drawings of findings.
Both collections are described in an RDF version of the Cidoc-crm model. The site uses facet navigation for findability of the objects.
In a test done with the ROB and the project Knowledge Infrastructure Cultural Heritage (KICH), the object descriptions of the glas collection were mixed with RDF/Cidoc-crm descriptions of buildings. Common factor was the location of the buildings and the finding sites of the glas objects.
Also in this test the Sesame RDF-framework was used for storage and facet navigation for retrieval.
In the above demos we show experiments with facet determination. With this type of determination, one can distinguish objects in a collection if these objects are descibed by a set of properties (facets) in such a way that each object has an unique combination of those properties compared to the other objects in the collection. At the user interface, facet navigation is used to select the properties.
The locust demo shows a small set (5 pieces) of dutch locusts. The glass demo shows a large set (562 pieces) of typological objects of archeological glass. Facet navigation makes the determination process a very easy and self explaining procedure.
The advantage of this method, compared to for instance classical dichotome determination is, that the sequence in which properties are selected is unimportant. Another advantage over dichotome determiniation is that facet determiniation is flexibel: changes in the collection of objects do not impose reprogramming of rules.