COLLECTION LEVEL METADATA, AND THE ADEPT LIBRARY ARCHITECTURE: A SOLUTION FOR CROSS-DATA CENTER SEARCHING, AND INFORMATION DISCOVERY

One of the core visions of the geosciences community has been the use of distributed data centers, where each data center either acts as a portal for regional, and/or topical information. At present, there is no consistent method of description for data center characteristics, contents, or access methods. From the library perspective, the lack of such standard information can make it difficult for users unfamiliar with a data center to determine if information in data centers content is applicable to their project. We also believe the lack of a standard description also hinders cross data-center search and discovery.

The Alexandria digital library (ADL) uses a standardized description for each collection, which we call “collection level metadata (CLM).” CML is a standard part of the ADL webclient interface. CLM differs from many other metadata standards, because it is about a data centers contents. CLM’s focus is on the aggregated information about collections and description of collection services such as search and discovery. CLM can assist users in determining how applicable the contents of a data center are to a project by providing simple summary information such as, title, scope, purpose, and responsible party, as well as aggregated information about the data center: item counts by format and object type, and histograms describing the spatial and temporal coverage.

We plan on developing features in the ADEPT library server (ALS) to utilize information in CLM to eliminate non-relevant collections from distributed queries. When discovery services are implemented in ALS clients will be able to retrieve approximate item counts prior to sending queries. Such information will let users expand or narrow the queries, and reduce the potential system impacts blindly sending queries to multiple distributed geospatial search services.

CLM fulfils a missing piece of the data center model; a consistent standardized description for the information about a data center, and its’ contents. The purpose of collection level metadata (CLM) is to provide a standard view of collection information, and facilitate federated cross-collection search and discovery. We propose that data centers adopt a consistent standard description whether or not they participate in the NSDL.