[Moims-dai] Response to rejection of SC234

D or C Sawyer Sawyer at acm.org
Mon Aug 27 00:28:52 UTC 2018

Dear All,

As I was not able to participate in last Tuesday’s teleconference where my proposal to eliminate SC222 was addressed, and given their conclusion that SC222 should be retained, I’m using this note to summarize my response. I believe this decision is short sighted and I hope that upon further reflection this decision will be reversed. However I will not submit another SC on this topic.

My response is divided into 3 categories:

 - Problems with arguments for SC222

 - Implications for the evolution of the OAIS RM

 - Some problems with the current incorporation of SC222

A.  Problems with arguments for SC222

The OAIS RM 2012 identifies an information grouping called PDI ( categories of Provenance, Context, Reference, Rights, and Fixity) as being important to the preservation of the associated Content Information.  These categories support preservation by documenting authenticity (Provenance, Fixity), identifying how the associated information is related to other information (Context) and thus improving understanding, identifying restrictions on usage (Rights) that may be in effect, and how information may be uniquely identified (Reference) in support of requests by Consumers.  Content Information itself is composed of the Content Data Object (CDO) and its associated Representation Information (Rep.Info.). This high level PDI association concept says nothing about how PDI is to be associated with the Content Information components CDO and Rep.Info. It also says nothing about how this association might be implemented. The various PDI categories could be applied separately to the CDO and to the Rep. Info, as well as to the combination, as makes sense based on the nature of the CDO and the Rep.Info.  In contrast, SC222 now restricts the PDI to only be associated with the CDO.

I’ve seen only two arguments put forward in support of this major change.

1. It is argued that it is virtually impossible to apply PDI to Rep. Info. and therefore it makes sense to limit its application in the Information Package to the CDO and thus exclude the Rep. Info. or the Content Information as a whole.  However in one of my email exchanges on this topic I outlined how databases and pointers could be used to track updates to Provenance, Context, and Rights Information for a Representation Network, and they also provide a degree of Fixity.   So clearly PDI application to a Rep.Info. network is implementable.  Also there can be no argument that the preservation of Representation Information, which varies greatly in complexity at the structural and semantic levels, and comes from a wide variety of sources, and often evolves, doesn’t benefit from an appropriate level of PDI application.  I can only speculate that the view that PDI for Representation Information is not implementable is based on a view that such implementations are not sufficiently close to the concept. However actual implementations must, by definition, be practical.  Any valid concept, and certainly the application of PDI to Representation Information is a valid preservation concept, will have some type of practical implementation.   

2. It was also argued that the auditors have not seen PDI being applied to Representation Information, so it is o’k to now take away that concept.  Assuming this is true, and most certainly it is not wholly true for all the PDI components, it must surely be strange to suggest that the practices of a few archives should now be taken to be the basis for what is conceptually significant for preservation.  A major, and so far successful, goal of the OAIS RM has been to encourage thought about what is involved in good preservation practices.  The OAIS RM has attempted to be the ‘Gold Standard’ context for the discussion of preservation issues both at its founding and in the previous updates.This has led to the recognition of the need for improvements in implementation practices and subsequently to the ISO auditing effort.  Thus this second argument is, at best, counter to the history of OAIS RM development to this point.

It is not a matter of whether applying SC222 is correct or not. It is a matter of whether this application is an improvement for the original objectives set out for the OAIS RM, or for some new objectives. The line of thinking that suggests the ease or difficulty of some aspect of implementation, rightly or wrongly perceived, should impact the evolution of the OAIS RM is totally new.  Following this line of thinking moves one from consideration of the OAIS RM as the conceptual ‘Gold Standard’ for preservation to something less.

It seems clear, at least to this author, that the use of the OAIS RM as the framework for ISO 16363 auditing, which in this context necessarily puts much of the OAIS RM into an implementation perspective, has resulted in some individuals active in the auditing to push an implementability perspective, rightly or wrongly conceived, back into the OAIS RM itself.   As previously noted, this was never a consideration in its original development or the previous updates.  What might this mean for the evolution of the OAIS RM?

B. Implications for the evolution of the OAIS RM

It is understandable that the ISO auditing process wants to have as much specificity as possible to aid both the auditors and the Archives. If the OAIS RM is now going to be evolved to be more closely aligned with the detailed experience of auditors, it will logically take a narrower view of what is supported and not supported through its concepts. This will evolve with auditor experience and with technology changes and implementation practices.  This OAIS RM could no longer be considered the conceptual ‘Gold Standard’ for the discussion of preservation issues.  For example, the adoption SC222 has just removed a very valid preservation concept, the use of PDI in helping preserve Rep.Info., from the OAIS conceptual model.  My view is that the preservation community needs to have a ‘Gold Standard’ reference model and PDI for Rep.Info. needs to be in it.

I believe that, lacking such a reference model, there may very well be competing models put forward, particularly in various disciplines, such as the library community, where there is already some concern that the OAIS RM is not always a good fit. One approach to this possibility is to clone an auditing version of OAIS that can evolve to better support the auditing while keeping a ‘Gold Standard’ OAIS that evolves more generally. Of course this would take resource that may not be available. Another approach is to take a rigorous approach to the separation of a ‘Gold Standard’ from the needs of auditing. If others have concerns along these lines, now would be a good time to speak up.  However in the grand scheme of important issues, the future of the OAIS RM is not significant.

C. Some problems with the current incorporation of SC222

If SC222 were not a major change to fundamental OAIS concepts, this could pretty well be ignored.  However as John has pointed out, this has resulted in over 200 changes from ‘Content Information’ to ‘Content Data Object’.  If I’ve counted correctly, through section 4.2 there were 33 reference to the CDO and now there are about 3 times as many (97). There were about 200 references to the Content Information and now there are about 138. This has put a greatly increased focus on the preservation of the Content Data Object,  which for a digital archive is mostly a matter of preserving the bits.  This is totally contrary to our past, successful, efforts to get the importance of the Representation Information more fully recognized. This has to be considered, at a minimum, ‘not helpful’ in this regard.

In addition, this change has complicated some relationships that show up in the new Terminology section.

1.  AIC definition:  The addition of the view that an AIC must include PDI describing the collection criteria and process, along with the view that all OAISs have at least one AIC which is the collection of all its AIPs, together with the new view that PDI only applies to the CDO and NOT the Rep Info, does not form a consistent picture.   PDI describing the collection criteria and process for a collection of AIPs is not PDI applied to the CDO.

Note also that this proposal, that an AIC must have this type of PDI, overlaps with the existing Collection Description that is supposed to provide this type of information.

2. Context definition: This is supposed to apply  only to the CDO and not the Content information.  But what is really going to be be documented, in many if not most cases, is the context for the Information, not just the CDO.  Generally people are not going to single out the CDO (when digital) versus the CDO + Rep when writing this information.  For example, a music performance has a relationship to other performances and this may well be documented Context.  To say this is about the CDO is not believable.  This attempt to focus on CDO instead of the Information has introduced this contrived awkwardness and is totally unnecessary.  This results from trying to use the CDO as a handle to refer to the Content Information without actually saying so.

3.  Fixity Information: The new definition only applies to the CDO.  Apparently it is not needed for Rep Info., but of course it I must be relevant to Rep. Info. preservation.  Any reasonable Archive will take some steps to preserve its Rep. Info. from undocumented alteration.

4. Preservation Description Information (PDI). As now proposed, it is only necessary for the preservation of the CDO.  However it clearly is needed for many types of Rep Info. as well.

5. Provenance Information: The new definition ignores that the history of Rep. Info. can be very important to its perceived authenticity.

6. Reference Information:  The new definition, applying only to the CDO, rules out its use for external references to the Rep. Info. and to the Content Information as a whole.  The example of ISBN clearly applies to the Content Information, not just to the CDO.

7. Transformation:  There is a new Note added that is incorrect.  The Content Information can be changed by updating of the associated Rep. Info. without requiring a change to the CDO.  For example, a new, broader, version of a standard format may be linked to the CDO that does not alter those aspects of the CDO that are present.  Another example is a new set of Semantic Information that does not alter the CDO.  According to the new definition of PDI, there is no need to track these changes because the PDI only applies to the CDO.  This seems clearly deficient.


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