Some people might have noticed that downloading the OAIS model from the CCSDS site now results in an improved version of OAIS 2012 http://public.ccsds.org/publications/archive/650x0m2.pdf Meanwhile this new standard is awaiting approval from ISO, which is expected in short notice. So we have now an updated version of the most important standard in digital preservation. The new version contains a change bar in the margin indicating the textual differences from the previous version. Personally I found it more convenient to have an overview of the main differences and created this summary. But please have a look yourself if you want to know the details.
The main changes are the following:
Access Rights Information
Access Rights information is added as an element to the Preservation Description Information. Access Rights information is not only restricted to access by the Consumer, but encompasses the permissions for preservation operations, distribution and usage of Content Information, so it offers a broader scope on the rights of an archive to handle material. Most of these will be regulated in the Submission Agreement with the Producer.
Emulation and relation to software
Emulation as a preservation strategy was a bit underestimated in OAIS-2002, but developments in emulation shown in various projects seems to have led to an higher appreciation of emulation as a strategy. At various places in the text it shows that migration is no longer the only strategy. Chapter 5 discusses emulation as a strategy to preserve access services or the original look and feel and explains how different varieties of emulation will fit in the OAIS model.
Preservation Planning Functional entity
There is more interaction between the Administration Functional Entity and the Preservation Planning Functional Entity. The Preservation Planning Functional entity will create preservation plans (and not only “migration plans” as mentioned in the previous version), based on its monitoring activity, and will send these to the Administration functional entity to be performed. But the Administration Functional Entity (cq. the function The Establish Standards and Policies) will also receive periodic risk analyses created by Preservation Planning to act upon, which gives the Preservation Planning Functional Entity a more active role in monitoring not only the outside world but also the OAIS itself. Interaction also takes place when Preservation Planning sends recommendations on AIP updates, and The Administration Functional Entity replies with preservation requirements (added to the already exisiting “migration goals and approved standards”). So for creating new migration packages not only the preservation requirements resulting from monitoring the Designated Community are input, but also the preservation requirements from Administration. In general some loose ends seems to be united here.
Authenticity and Information Properties
The confusing use of the word “authentication” has now changed and the term “authenticity” is defined (adding the much used definition of “The degree to which a person (or system) regards an object as what it is purported to be.” With an important addition: “ Authenticity is judged on the basis of evidence.” Two paragraphs describe ways to create this evidence. One of the ways lies in the new concept of Transformational Information Properties . A Transformation was already defined as a digital migration where the bits of the Content Object and/or the PDI change, ultimately resulting in an AIP version. This is a risky operation as you might loose important information contained in the original AIP. By defining Transformational Information Properties, you can define beforehand which properties need to be kept after the transformation. The fact that these properties are still there in the new AIP version will contribute to the Authenticity of the object. The Information Property is related to the commonly known but not always clearly defined term “significant property”, but I think more discussion is needed to define better where the differences and similarities between the two concepts lie and how to translate this into the daily practice.
Definition Information package
The term Information Package is redefined to : “ A logical container composed of optional Content Information and optional associated Preservation Description Information. Associated with this Information Package is Packaging Information used to delimit and identify the Content Information and Package Description information used to facilitate searches for the Content Information.”
(original definition: The Content Information and associated Preservation Description Information which is needed to aid in the preservation of the Content Information. The Information Package has associated Packaging Information used to delimit and identify the Content Information and Preservation Description Information.)
A new definition is introduced “Other Representation Information” and described as “Representation Information which cannot easily be classified as Semantic or Structural. For example software, algorithms, encryption, written instructions and many other things may be needed to understand the Content Data Object, all of which therefore would be, by definition, Representation Information, yet would not obviously be either Structure or Semantics. Information defining how the Structure and the Semantic Information relate to each other, or software needed to process a database file would also be regarded as Other Representation Information.” The more variety and complexity in digital material to preserve, and the growing understanding on what we need to describe to keep the material accessible and understandable, the more we will need to adapt the standard.
Chapter : Preservation Perspectives
This chapter is adapted with the above mentioned changes and refines the definitions for an AIP version (An AIP whose Content Information or Preservation Description Information has undergone a Transformation on a source AIP and is a candidate to replace the source AIP. An AIP version is considered to be the result of a Digital Migration.) versus an AIP edition (An AIP whose Content Information or Preservation Description Information has been upgraded or improved with the intent not to preserve information, but to increase or improve it. An AIP edition is not considered to be the result of a Migration.)
Minor additions are for example the mentioning of “temporary storage” to place information packagages that are in the midst of a process.
This updated version of the OAIS standard was published almost 10 years after the first publication. The worldwide research done in digital preservation and the insights gained from that research will expect that the 5 year review period of ISO will be needed to keep the OAIS model in pace with the developments.
[i] Reference Model for an Open Archival Information System (OAIS). Magenta Book. Issue 2. June 2012.