Metadata Spaces Wason & Wiley 1 05/15/06 Journal of Internet Cataloging 2000 [in Press]. 3 [1-3] and Metadata and Organizing Educational Resources on the Internet J. Greenberg (Ed.) 2001, pp. 263-278 Haworth, NY Structured Metadata Spaces DRAFT Thomas D. Wason, IMS Global Learning Consortium, Inc. (Now www.twason.com ) David Wiley, Brigham Young University 1. Introduction This paper will present the concepts of a metadata space as it relates to cataloging and discovery. A space has multiple dimensions; in the case of resource metadata, these are descriptive dimensions. We will explain the needs for orthogonal descriptive dimensions, and present a method for achieving maximally efficient, independent dimensions using semantic structures realized in structured metadata. A specific example of this system as developed in the IEEE Learning Technology Standards Committee (LTSC P1484) Learning Object Metadata (LOM) will be presented. The LOM is the collaborative work of many organizations including ADL, AICC, ARIADNE, GESTALT, and IMS. The scope of the concepts presented in this paper encompasses general concepts of metadata systems. 2. The Problems In order to understand the requirements for a metadata system, the nature of the problems such a system addresses needs to be understood. The user community encompasses a wide variety of needs, not all of which can be predicted by the cataloging community. The user may be a teacher searching for individual resources or complete courses. It may also be a student looking for references for a paper or doing research for a project. (A data management system may be considered a special form of user.) Metadata can be considered a system that supports communications between two very diverse user communities. As a communications system it must have a well-defined vocabulary and syntax to support a wide variety of semantic needs. There is inherent variability in the use of a communication system: interpretation of the language may vary with individuals and/or may drift over time. This variability creates a certain lack of clarity in the communications, or “fuzziness.” Additionally, the purposes filled by the system may change, causing the system itself to change to fulfill these new requirements. 2.1. Communication Bibliographic metadata can be considered to be a system of communication between the cataloging community and the user community. The cataloging community ranges from the professional cataloger who describes a large number of resources on a daily basis to the casual creator of metadata who may want to provide some meaningful labels for a web page. Together, the community of catalogers creates a corpus of metadata. There is a strong need for a common language that has adequate richness but will not fall apart due to the noise inherent in the system. Metadata is a poor personal communications system, as the cataloger cannot know exactly for what purpose every user will want a resource. Additionally, the user cannot ask for information that does not exist. As the communication becomes more uni-