There have been a variety of attempts to solve the general semantic interoperability problem through the creation of an abstract scheme in which specific vocabularies can be subsumed as particular cases of the scheme. Translation between any two vocabularies is then handled by using the abstract scheme as an intermediary. That is, a translation from a given specification X to specification Y is accomplished by translating specification X to the abstract scheme and then from the abstract scheme to specification Y. The existence of such an abstract scheme renders unnecessary direct translations between specifications, which would grow rapidly in number as the number of specifications increases. [2-4] Of course, constructing an abstract scheme that can accurately subsume all specific vocabularies of interest remains a major unsolved challenge. Nevertheless, projects that aim to solve the semantic interoperability problem in the large are valuable since the desire to work seamlessly with the multiplicity of digital content in varied formats will continue to grow.
Meanwhile, the IU has been pursuing a pragmatic approach to enhancing semantic interoperability among libraries, educational technology, and web syndication. By focusing on a small number of XML-based interoperability specifications that are of importance in the various domains, we have written direct crosswalks between the specifications, thereby avoiding the need for an abstract scheme. In our work, we have produced baseline translations, rather than crosswalks of the highest fidelity. We have transported materials between library repositories and instructional technology applications via these functional converters for three purposes: 1) to demonstrate the interchange of digital content between libraries and instructional technology systems; 2) to learn from practitioners in the educational and library communities where to invest further effort in making the crosswalks useful in production services; and 3) to encourage the developers of interoperability specifications in the library and educational technology communities to harmonize related specifications where possible, thus reducing the need for crosswalks in the first place. This project will enable the IU to make further progress on these three fronts.
