Annotated Literals for Standard Units of Measurement

Abstract. In our experiences building systems that use Semantic Web technologies, we have often identified a requirement for a consistent way to associate data values with standard units. We have tried a number of solutions to this issue, each of which has its own benefits and drawbacks in terms of complexity, expressivity, and clarity. In this paper, we present a discussion of the issue and a proposal for a simple extension to OWL/RDF to support the annotation of literal values with standard SI units that meets our needs without introducing many of the drawbacks of alternate approaches