[Moims-dai] FW: Telecon Notes?

David Giaretta david at giaretta.org
Mon Jul 9 11:12:03 UTC 2018

Hi all

I missed the call on which these notes report, but I must make a few comments which I am sure I would have made in the meeting.

In summary Don's arguments about the Information Model seem to derive from examples of some specific Data Objects, without explicit consideration of the Designated Community, which I argue is misleading, and can be addressed by adding text to the standard to address such "edge cases", as discussed next.

The argument about whether or not a Data Object needs Representation Information in order to be understood is misleading in that, as I responded in a previous email, it depends on the Designated Community. In other words, if the Data Object is a piece of paper written in English, and members of the Designated Community can read and understand English then there is no need for an explicit English dictionary because the Designated Community's Knowledge Base includes that. 

However, if the Designated Community were to be defined as readers of Chinese then Representation Information such as an English Dictionary would be needed. So, if one claims that this piece of paper does not need Representation Information then that is in the context of a Repository's definition of a specific Designated Community. 

So in general modelling terms the OAIS Information Model is right - a Data Object needs Representation Information in order to be used/understood. However there may be some specific instances where, for a specific Designated Community, explicit Representation Information is not needed.

In modelling terms, I would regard cases such as English written on paper to be read by English readers as an "edge case" and to be consistent in such edge cases one should say that the Representation Information is the statement that "for the specific Designated Community no additional explicit Representation Information is currently needed". As far as I can see this would make the model complete and consistent. We could add some wording to the discussion of Representation Information and Designated Community to make this clear.

In terms of the idea of OAIS being only a "communications framework" - yes it is that, especially the Functional Model, but it also provides something more, namely guidance of what one needs in order to preserve digitally encoded information, and OAIS lays these out in terms of conformance. Thus, the repository needs an AIP with all its components; it needs to undertake all the Mandatory Responsibilities. 

I realise that to some readers all this may seem like a very abstruse, uninteresting discussion. However, it IS important because there will be times when repository staff will come across puzzling cases and we need to make sure, as far as humanly possible, that OAIS provides useful, correct and consistent guidance when read carefully.
Hope that helps


-----Original Message-----
From: MOIMS-DAI <moims-dai-bounces at mailman.ccsds.org> On Behalf Of John Garrett
Sent: 07 July 2018 05:55
To: 'MOIMS-Data Archive Interoperability' <moims-dai at mailman.ccsds.org>
Subject: [Moims-dai] FW: Telecon Notes?

-----Original Message-----
From: Don Sawyer [mailto:topcottageguys at gmail.com] On Behalf Of D or C Sawyer
Sent: Monday, July 2, 2018 8:18 AM
To: John Garrett <garrett at his.com>
Cc: Hughes, John S (398B) <John.S.Hughes at jpl.nasa.gov>; Mark Conrad <Mark.Conrad at nara.gov>
Subject: Re: Telecon Notes?

Hi John,

I’ve made a few comments to your comments.  I think our differing views are pretty clear.  If you want to add some more comments, or not, I have no objections to your sending this out to the wider group.


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