Chronopolis Audit Report 2012

Chronopolis: Methodology and Criteria

This assessment was undertaken to determine whether or not Chronopolis meets the commitments it has made in regard to the long-term preservation of digital data for the research community and whether the repository complies with established criteria for trusted digital repositories. The assessment included a site visit, a review of the information independently gathered by CRL from published and unpublished sources, and a review of documents and documentation provided by Chronopolis.

CRL conducted its audit with reference to:

  • generally accepted best practices in the management of digital systems
  • the interests of the CRL community of research libraries
  • the practices and needs of scholarly researchers in the humanities, sciences, and social sciences in the United States and Canada
  • the criteria included in Trustworthy Repositories Audit &Certification: Criteria and Checklist
  • the Open Archive Information System reference model  (OAIS)
  • other metrics developed by CRL through its analyses of digital repositories.

The primary metrics used by CRL in such assessments are those specified in the Trustworthy Repositories Audit and Certification (TRAC) checklist.  TRAC was developed by a joint task force created by the Research Libraries Group (RLG) and the National Archives and Records Administration in 2003 to provide criteria for use in identifying digital repositories capable of reliably storing, migrating, and providing long-term access to digital collections.  TRAC represents best current practice and thinking about the organizational and technical infrastructure required for a digital repository to be considered trustworthy and thus worthy of investment by the research and research library communities.

CRL assessed Chronopolis on each of the three categories of criteria specified in TRAC and has assigned a level of certification for each. The numeric rating (below) is based on a scale of 1 through 5, with 5 being the highest level, and 1 being the minimum certifiable level.   (The minimal certification rating of 1 is assigned in instances where a repository has inconsistencies or deficiencies in areas that might lead to minor defects of a systemic or pervasive nature, but where no major flaws are evident.)

TRAC Category




Organizational Infrastructure



Digital Object Management



Technologies, Technical Infrastructure, Security






The basis for assignment of these ratings is provided in Section B, Detailed Audit Findings, below.

It should be noted that CRL certification of Chronopolis applies specifically to the repository’s ability to preserve and manage at the bit level digital social science, atmospheric and geospatial data from a variety of sources. CRL did not assess Chronopolis procedures and processes for normalizing, migrating, or otherwise altering and preserving data for distribution via future platforms or devices.