Now that we have a better grasp of the IT and informatics challenges of a distributed and interoperable information network, we can think more again about its adoption - how to make it work and useful on the ground. Following was our rough chain of thought on metadata:

• We decided that massive amounts of useful metadata are necessary to jump-start USGIN. The reason for pursuing structured metadata is to enable smarter (and spatial) searching, provide more useful information for resource evaluation, and to enable automated access to services from clients.
  
  • Metadata creation and maintenance frustrations leads to fewer and less useful (bad) metadata records; hence, they are a barrier to cyberinfrastructure adoption and the creation of better client/server tools.
    • This leads us to believe that a minimum useful metadata record (not necessarily the same as a formal metadata standard's minimum requirements) is better than no metadata or even better than verbose and crappy metadata.
      • To help our data providing partners with creating new metadata records and maintaining them, we need tools that make their life easier and their metadata efforts more rewarding.
        • Although USGIN uses ISO 19139 in its CSW metadata catalogs, FGDC and possibly other metadata standards are used or required by partners.
          • ...

We decided on prototyping a "generic minimum metadata wizard" that stores minimum useful metadata in a format agnostic data model which allows one to export (download/services) the conceptual metadata records into any number of arbitrarily formatted metadata files. The minimum metadata requirements are designed to balance the need for on-line, interoperable metadata discovery and distribution with the cost of generating digital metadata. In order to effectively advertise the USGIN partner's resources, metadata records must accomplish three major goals:

1. Describe the digital or physical resource or service.
2. Credit the owner, author, originator, or responsible party of the resource.
3. Provide access information to the described resource.

Following is our latest stab at the conceptual metadata model which is based on Dublin Core and is expanded according to practical needs.

Conceptual Minimum Metadata Fields

Key: Groupings; required, conditional, and optional metadata fields; (number of values that can be specified).

• Citation
  • Title (1 entry): Succinct (preferably <250 characters) name of the resource.
  • Description (1 entry): Inform the reader about the resource's content as well as its context.
  • Originators (1 to many entries): Authors, editors, or corporate authors/curators of the resource.
  • Publication Date (1 entry): Publication, origination, or update date (not temporal extent) for the resource. Use a "year" or ISO 8601 date and time format. Alternative date formatting must be machine readable and consistent across all datasets.
  • Keywords (0 to many entries): Thematic, spatial and temporal free-form subject descriptors for the resource. A keyword may be assigned on metadata import if none are present.
  • Resource language (0 to 1 entries): Use three letter ISO 639-2 language code (defaults to "eng" for English).
  • Resource ID (0 to many entries): Resource identifier(s) following any public or institutional standard. 
  • Intellectual Originator Contact (0-1 entry): The primary party responsible for creating the resource. Organization name, person name, street address, city, state, ZIP code, email, phone, fax.
  • Bibliographic Citation (0 to 1 entries):  Full bibliographic citation if the resource has been published.
• Geographic Extent - Horizontal (1 entry, point or minimum bounding rectangle): north bounding latitude, south bounding or point latitude, east bounding longitude, west bounding or point longitude. Values given in decimal degrees using the WGS 84 datum. A minimum bounding rectangle will be created if point coordinates are given.
• Geographic Extent – Vertical (0 to 1 entries): surface elevation, maximum elevation, minimum elevation. Values given in meters relative to mean seas level (MSL) using the EPSG::5714 geodetic parameter (WGS 84).
• Temporal Extent – Temporal range over which the resource was collected or is valid. If the resource pertains to specific Geologic time periods, those terms should be entered as keywords.
  • Start date (0 to 1 entries): Use ISO 8601 date and time format.
  • End date (0 to 1 entries; required if start date exists): Use ISO 8601 date and time format.
• Resource
  • Link to the resource (0 to 1 entries): A URL pointing to a resource or resource webpage.
  • Access instructions (0 to 1 entries): A sentence or paragraph describing how to access the information.
  • Distribution Contact (1 entry): The party to contact about accessing the resource. Organization name, person name, street address, city, state, ZIP code, email, phone, fax, URL.
  • Quality statement (0 to 1 entries): describe the quality of the resource.
  • Constraints statement (0 to 1 entries): describe the resource's legal and usage constraints.
  • Lineage statement (0 to 1 entries): describe the resource's provenance.
• Metadata
  • Metadata Date (1 entry): Last metadata update/creation date-time stamp in ISO 8601 date and time format. This may be automatically updated on metadata import if a metadata format conversion is necessary.
  • Metadata UUID (0-1 entries): A Universally Unique Identifier (UUID) will be assigned during the metadata import process if one is not provided. Unique identification of each metadata record is required to avoid duplicate entries across multiple metadata catalogs. The UUID format provides unique identification without centralized coordination.
  • Metadata Contact (1 entry): The party to contact with questions about the metadata itself. Organization name, person name, street address, city, state, ZIP code, email, phone, fax, URL.

Files: 

Draft recommendations for simple metadata for geoscience resources. Includes enumeration of use cases that motivate requirement.