Portico is one of several organizations providing digital preservation services for the academic community. We know that you need to evaluate options and that doing so can be challenging.
Below we offer some help by providing a comparison of participation and the content in Portico to other services as well as a report on how Portico meets key factors necessary for digital preservation established by third-party preservation experts, Anne Kenny and Richard Entlich, and first published by CLIR in 2006. Factual information on other services is gathered and updated from public sources.
| Portico | HathiTrust | CLOCKSS | LOCKSS | |
|---|---|---|---|---|
| Participating Publishers | 91 (on behalf of over 2,000 societies and associations) | Unknown | 21 | 411* |
| Participating Libraries | 657 | 25 | 38 | 200 |
| Committed E-Journals | 10,792 | Unknown | Unknown | ~2,900 |
| Committed E-Books | 33,246 | Unknown | Unknown | Unknown |
| Committed D-Collections | 10 | 0 | 0 | 0 |
| Titles Accessible | 4 | 5,342,028 volumes | 3 | Unknown |
| Institutions Receiving PCA | 3 | N/A | N/A | Unknown |
| Titles Fulfilling PCA | 22 | N/A | N/A | Unknown |
| * There is no machine actionable version of the titles and publishers committed to LOCKSS. In December 2009, Portico staff manually walked through the title list at http://www.lockss.org/lockss/Publishers_and_Titles to create a spreadsheet that was then used in the analysis presented here. | ||||
| Portico | HathiTrust | CLOCKSS | LOCKSS | |
|---|---|---|---|---|
| Archival Units | 14,918,003 e-journal articles & books | 5,342,028 volumes | Unknown | Unknown |
| E-Journals Archived | 14,812,189 | Unknown | Unknown | 1,185* |
| E-Books Archived | 1,940 | Unknown | Unknown | Unknown+ |
| Files Archived | 175,283,383 | 1,869,709,800 pages | Unknown | Unknown |
| Images Archived | 84,016,315 | 1,869,709,800 pages | Unknown | Unknown |
| Repository Created Archival Files | 43,563,405 | Unknown | Unknown | Unknown |
| Supplied Text Files | 31,164,819 | Unknown | Unknown | Unknown |
| Application Specific Files | 16,277,552 | Unknown | Unknown | Unknown |
| Multi-File Packages | 137,577 | Unknown | Unknown | Unknown |
| Video Files | 20,467 | Unknown | Unknown | Unknown |
| Audio Files | 570 | Unknown | Unknown | Unknown |
| Executable Files | 1 | Unknown | Unknown | Unknown |
|
* This number assumes that those titles which are not labeled as “in process” on the LOCKSS title list are being crawled and preserved in LOCKSS boxes. + In August 2009, Portico was able to review the home page of a LOCKSS box at an ARL library. At that time there were just over 6,000 archival units or AUs available for crawling. In general, LOCKSS seems to consider the AU to be the issue. The full LOCKSS cache on this box was approximately 500 GB. In August 2009, Portico’s archive was 14 TB and contained over 13 million articles from 7,542 e-journal titles and nearly 2,000 e-books. |
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| Evaluation Factors | Portico Response |
|---|---|
Mission and MandateThe repository should have both an explicit mission and the necessary mandate to perform long-term archiving. |
Portico preserves scholarly literature published in electronic form and ensures that these materials remain accessible to future scholars, researches, and students. This purpose statement can be found on the Portico website. Portico is part of ITHAKA, a not-for-profit organization with a mission to help the academic community use digital technologies to preserve the scholarly record and to advance research and teaching in sustainable ways. |
Organizational ViabilityRepositories must be organizationally viable. Three attributes in particular relate to the viability of any archiving effort: administrative responsibility, organizational viability, and financial sustainability. |
In terms of administrative responsibility, Portico’s content model and processes are informed by a number of community standards, including: Metadata Encoding & Transmission Standard (METS), Digital Item Declaration Language (DIDL – a part of the MPEG-21 standard), Reference Model for an Open Archival Information System (OAIS), and Trustworthy Repositories Audit & Certification: Criteria and Checklist (TRAC). Portico has committed to ongoing preservation audits by the Center for Research Libraries and provides regular updates to the library and publisher communities about the status of content preserved in Portico. In terms of organizational viability, Portico is committed to preserving content for the long-term as reflected in Portico’s purpose statement and license agreements. In terms of financial stability, Portico has a diversified funding stream from 657 libraries and 91 (representing over 2000 societies and associations) and a commitment to good business practices with short- and long-term financial planning, including annual financial audits. |
NetworkRepositories will work as part of a network. |
Portico believes that collaborative development is a keystone of success. Portico and the Koninklijke Bibliotheek (National Library of the Netherlands – KB) have an agreement whereby the KB preserves an off-line copy of the Portico archive. Portico consults regularly with the KB, the Library of Congress, the British Library, and other members of the digital preservation community. Portico is a participant in the development of JHOVE2 (a file characterization tool) and the Unified Digital Format Registry (UDFR). Portico worked closely with other organizations on the development of the PREMIS (PREservation Metadata: Implementation Strategies) data dictionary and works closely with the National Library of Medicine on the development and maintenance of the Journal Archiving and Interchange Tag Suite. |
| Evaluation Factors | Portico Response |
|---|---|
Rights and ResponsibilitiesRights and responsibilities associated with preserving e-journals should be clearly enumerated and remain viable over long periods. |
Portico has license agreements with the publishers that allow us to preserve the content for the long-term (including migrating or transforming the content as necessary) and deliver the content should specific trigger events occur. Portico license agreements also grant Portico the right to name a successor, not-for-profit organization. Portico also has license agreements with participating libraries. |
Content CoverageThe repository should be explicit about which scholarly publications it is archiving and for whom. |
Portico aims for transparency in its actions and content. The content committed to Portico is available on the Portico website. In addition, the specific holdings that are currently preserved in the archive are available. Portico also offers a holdings comparison service which allows libraries to compare their holdings to the Portico holdings and identify overlap. Portico supports the work of PEPRS to build an e-journals preservation registry service. |
| Evaluation Factors | Portico Response |
|---|---|
Minimal ServicesE-journal archiving programs should be assessed on the basis of their ability to offer a minimal set of well-defined services. |
Portico’s preservation services are outlined in our license agreements with libraries and publishers. Our work includes: preservation planning, receipt and inventory management, processing and archival deposit, long-term monitoring and management, and content delivery when specific trigger events occur. A step-by-step guide to preservation at Portico is available. |
Access RightsA repository should negotiate with publishers to ensure that the digital archiving program has the right, and is expected, to make preserved information available to libraries under certain conditions. |
Titles preserved within Portico become broadly available for use to the faculty, staff, and students at participating institutions when specific trigger events occur:
In addition, Portico can provide post-cancellation access (also referred to as perpetual access) to titles in cases where the publisher has selected Portico as a means of providing such access. |
| Evaluation Factors | Portico Response |
|---|---|
Preservation ApproachThe approach of the organization to digital preservation should be robust and proven. |
Portico’s migration based approach is designed to address long-term preservation needs. Portico repackages all content into archival information packages. Throughout this repackaging process, Portico gathers preservation metadata (including event, technical, and descriptive metadata). Together, the uniform packaging and the preservation metadata allow us to manage the content over the long-term. Over time Portico will ‘migrate’ or transform content from one file format to another as technology changes. For e-journals, Portico performs two initial migrations on each article, one to transform the publisher’s mark-up into the NLM archival standard and the other to repackage the content into an archival information package – as of September 2009, Portico had performed over 26 million migrations. |
Third Party AuditRepositories should be accredited by the Center for Research Libraries (CRL) or other accrediting agencies. |
Portico has been certified a a trustworthy digital repository by the Center for Research Libraries (CRL). Portico is the first preservation services to have undergone an in-depth assessment by the CRL following the general metrics found in the Trustworthy Repositories Audit & Certification: Criteria and Checklist (TRAC) |
Local Support RequirementsDepending upon approach, preservation services may require local support and maintenance. |
Portico allows participating libraries to request four auditor user accounts. These user accounts allow librarians to audit or review content in the archive. Library auditors may audit as much or as little as they deem necessary. |