2. Existing semantic web approaches

A number of cultural heritage bodies (e.g. British Museum, Riksantikvarieämbetet) have produced Semantic Web resources which can be used to search collections for meaningful concepts within their collections. These have been increasingly incorporated into larger-scale projects such as Europeana which allow for the simultaneous searching of multiple collections.

The basis for these approaches the underlying technology is the Resource Description Framework (RDF), an XML application which adds a semantic component to the kind of linking that the web is built on. RDF constructs the link in the form of a ‘triple’, a subject-predicate-object structure, where all three elements are defined by resources on the web. This allows not only for the linking of resources but defining the nature of that link via the predicate. A normal hypertext link, conversely, expresses a relationship between two web resources (the page viewed and the page that the link connects to) without defining in any formal way the nature of that relationship.

For organisations which deal mainly in non-textual phenomena, this approach is important for a variety of users to find materials by textual searches without having to know inventory numbers or other non-semantic identifiers. The British Museum, for example, allows the searching of the collections according to period, find spot, material and names and events associated with the object.

Image link to British Museum: Franks Casket

One such object is the Franks Casket (BM 1867,0120.1), which will appear in searches on the British Museum site with links to and from whalebone objects, middle Anglo-Saxon objects and representations of the legendary smith Weland and other figures on the casket. The ability to find such objects by semantic searches is extremely useful, but is still problematic for a systematic study of the northern myths and legends depicted on the casket. Some of the pictures on the casket are not indexed, particularly where the images are not reliably identifiable. The lid, for example, has a scene with the runic caption ægili (Egill?). The picture no doubt relates to a legendary narrative but is not linked to any index, presumably because of the uncertainty of the attribution.

Additionally, the picture on the Franks Casket which is identified as Weland by the web resource is not self-evident: in this case there is no caption identifying the persons represented or the scene. The process by which an object is linked to a figure who appears in textual sources is a complex one involving several stages of interpretation based on literary sources, although it is a well-established interpretation. The identification of Weland here may preclude other interpretations, particularly ones that do not link an image to a particular figure or narrative. The goal of this paper is to present ways in which the semantic linking process can be made explicit and the stages of interpretation, analysis and synthesis can be encoded.

A project with similar similar challenges to PCRN is the project ‘Skaldic Poetry of the Scandinavian Middle Ages’: it is also based on a body of evidence that requires a large amount of analysis and interpretation to be made accessible to a wide audience of scholars and the general public. The skaldic database links manuscripts, inscriptions, transcriptions, editions and a textual and critical apparatus in order to make accessible every stage of the editing and analytical process in understanding the poetry. It brings together as transparently as is possible the connection between the material evidence for the poetry and the putative oral form of the poetry and its context of production.

While complex, skaldic poetry is nevertheless a textual and linguistic phenomenon; the study of pre-Christian religions requires the analysis of visual and spatial phenomena and has as its goal the reconstruction of belief systems and human practices. The corpus of materials for mythology and religion is therefore even broader and requires different approaches for different sources. This paper proposes ways in which these different approaches can be synthesized in a coherent data structure.

References