Is 'Quality' Metadata 'Shareable' Metadata? The Implications of Local Metadata Practice on Federated Collections

Introduction The federation of digital resources has become increasingly important in realizing the full potential of digital libraries. Federation is often achieved through the aggregation of descriptive metadata, therefore the decisions resource developers make for the creation, maintenance, and quality assurance of their metadata can have significant impacts on aggregators and service providers. Metadata may be of high quality within a local database or web site, but when it is taken out of this context, information may be lost or its integrity may be compromised. Maintaining consistency and fitness for purpose are also complicated when metadata are combined in a federated environment. A fuller understanding of the criteria for high quality, “shareable” metadata is crucial to the next step in the development of federated digital libraries. This study of metadata quality was conducted by the IMLS Digital Collections and Content (DCC) project team (http://imlsdcc.grainger.uiuc.edu/) using quantitative and qualitative analysis of metadata authoring practices of several projects funded through the Institute of Museum and Library Services (IMLS) National Leadership Grant (NLG) program. We present a number of statistical characterizations of metadata samples drawn from a large corpus harvested through the Open Archives Initiative (OAI) Protocol for Metadata Harvesting (PMH) and interpret these findings in relation to general quality dimensions and metadata practices that occur at the local level. We discuss the impact of these kinds of quality on aggregation and suggest quality control and normalization processes that may improve search and discovery services at the aggregated level.