Encoding Application Profiles in a Computational Model of the Crosswalk

Abstract

OCLC's Crosswalk Web Service (Godby, Smith and Childress, 2008) formalizes the notion of crosswalk, as defined in Gill, et al. (n.d.), by hiding technical details and permitting the semantic equivalences to emerge as the centerpiece. One outcome is that metadata experts, who are typically not programmers, can enter the translation logic into a spreadsheet that can be automatically converted into executable code. In this paper, we describe the implementation of the Dublin Core Terms application profile in the management of crosswalks involving MARC. A crosswalk that encodes an application profile extends the typical format with two columns: one that annotates the namespace to which an element belongs, and one that annotates a 'broader-narrower' relation between a pair of elements, such as Dublin Core coverage and Dublin Core Terms spatial. This information is sufficient to produce scripts written in OCLC's Semantic Equivalence Expression Language (or Seel), which are called from the Crosswalk Web Service to generate production-grade translations. With its focus on elements that can be mixed, matched, added, and redefined, the application profile (Heery and Patel, 2000) is a natural fit with the translation model of the Crosswalk Web Service, which attempts to achieve interoperability by mapping one pair of elements at a time.