[Moims-dai] Interoperability, Data, Information, and the DC

david at giaretta.org david at giaretta.org
Sun Jan 17 20:16:12 UTC 2021

Hi Mike


My email of 12th Jan was about the definition of interoperability, and if I
raised "data" vs "information" it was just to illustrate some different
possibilities of defining interoperability. I make it clear at the end what
my preference is.


But to answer your email I think it is easier if we avoid mixing up

a.	what the OAIS-IF makes possible and
b.	what any particular archive can provide


If there is lots and lots of Representation Information then OAIS-IF makes
it possible for people to do lots and lots - great.


Of course if a source of information does not have the Representation
Information that an information consumer would like then that is tough -
OAIS-IF cannot magic things out of thin air. 


In terms of talking about data vs information, clearly OAIS makes a
distinction. However, in terms of OAIS-IF it surely will be less confusing,
in terms of design and implementation to simply allow the possibility (as
mentioned above) that there may not be as much Rep.Info. as the information
consumer may want. Of course where one needs to get the bits (the Data
Object) then OAIS-IF must allow this.


Then we don't really have to worry about the Designated Community (DC) in
the OAIS-IF design because OAIS would guarantee that a conformant archive
has enough Rep.Info. for the DC of that piece of information, but not for
anyone/anything else.


As you can see, my preference is to be aware of the complexities but have a
"get out of jail" card (i.e. recognise that there is the possibility that
there may not be enough Rep.Info.) so that we can mostly ignore those
complexities when we design OAIS-IF. This makes the design much simpler. I
am sure that if one thinks it through then it will all work fine. 


Surely this is what good design/modelling should be about i.e. do not model
every possible detail but do model enough detail. "Enough" is a matter of
judgement. I hope it is clear what my judgement is.




From: MOIMS-DAI <moims-dai-bounces at mailman.ccsds.org> On Behalf Of
kearneysolutions at gmail.com
Sent: 17 January 2021 19:36
To: 'MOIMS-Data Archive Interoperability' <moims-dai at mailman.ccsds.org>
Subject: [Moims-dai] Interoperability, Data, Information, and the DC


(Changed subject line from the thread below)


There weren't any other responses to David's note below, and we did touch on
data vs. information in the last telecon, but I don't think we resolved
anything.  Correct me if I'm wrong on that.  


I think that the discussion below would benefit form addition of the
"Designated Community".  Moreover, I think what we can promise from OAIS-IF


For the Designated Community, an OAIS-IF archive provides interoperability
of information.  (OAIS RM requires that the designated community can
understand the content of DIPs).  


For those outside the designated community, OAIS-IF only guarantees
interoperability of data.  OAIS-IF allows access and retrieval of data, but
the OAIS-RM compliant archive doesn't guarantee it has the Representation
Information that can be interpreted by those outside the designated


In the latter case, if an OAIS RM compliant archive wants to go the extra
mile and provide Representation Information that even (*some?*) consumers
from outside the Designated Community can understand, then they are welcome
to do that.  But they are not required.  Therefore interoperability of
information is provided for the Designated Community and perhaps others.
But it may be that only interoperability of data is provided outside the
Designated Community.  


Does that ring a bell? (good or bad?)  


   -=- Mike


Mike Kearney

Huntsville, Alabama, USA 


From: MOIMS-DAI <moims-dai-bounces at mailman.ccsds.org
<mailto:moims-dai-bounces at mailman.ccsds.org> > On Behalf Of
david at giaretta.org <mailto:david at giaretta.org> 
Sent: Tuesday, January 12, 2021 5:58 AM
To: 'MOIMS-Data Archive Interoperability' <moims-dai at mailman.ccsds.org
<mailto:moims-dai at mailman.ccsds.org> >
Subject: Re: [Moims-dai] Reminder of Skype call tomorrow


Hi John


One immediate, absolutely fundamental, question arises from your comments,
for example your first comment:

Although information exchange rather than data exchange is an admirable
goal, I thought main purpose of OAIS-IF was interoperability. I think we
should be aiming for interoperability whether information or data is


The question is "What is interoperability?". We need to agree on that
otherwise we are talking at cross-purposes.


http://interoperability-definition.info/en/ has a definition:

Interoperability is a characteristic of a product or system, whose
interfaces are completely understood, to work with other products or
systems, present or future, in either implementation or access, without any


My understanding was that to have interoperability of information from
different domains, say Solar studies and Meteorology, one needed to be able
to "combine" ("work with") the information from those domains e.g. plot the
heat output from the Sun against weather patterns to see if Global Warming
is caused by the Sun rather than Man. This requires more than just getting
the data - which one can probably do already pretty easily. My belief was
that this is why we are talking about an OAIS-IF - because one of the OAIS
fundamental drivers is about understandability and usability.


Maybe some would think that interoperability is just finding relevant
information e.g. where are is Solar energy output data? Well there are lots
of things that exist already e.g. Google.


Maybe some would think that interoperability is just getting the data from
multiple domains together. Well again that is pretty easy right now. Besides
which isn't the fundamental point in OAIS that we need more than the Data


My question is "What does an OAIS-IF need to do?" in other words , what is
the link to OAIS? Since we said this was not about the internals of the
archives, OAIS-IF is not about the details of preservation, except when one
os transferring (copies of) AIPs to another archive as part of the
preservation strategy. 


To my mind the answer is that it has to deal with
understandability/usability of the information which is encoded in data,
together with evidence about Authenticity.  


Perhaps we can discuss this today.






From: MOIMS-DAI <moims-dai-bounces at mailman.ccsds.org
<mailto:moims-dai-bounces at mailman.ccsds.org> > On Behalf Of garrett at his.com
<mailto:garrett at his.com> 
Sent: 12 January 2021 02:40
To: 'MOIMS-Data Archive Interoperability' <moims-dai at mailman.ccsds.org
<mailto:moims-dai at mailman.ccsds.org> >
Subject: Re: [Moims-dai] Reminder of Skype call tomorrow




Great start.


I've added a number of comments to help move it forward.


Hope, Health, and Peace,



From: MOIMS-DAI <moims-dai-bounces at mailman.ccsds.org
<mailto:moims-dai-bounces at mailman.ccsds.org> > On Behalf Of
david at giaretta.org <mailto:david at giaretta.org> 
Sent: Monday, January 11, 2021 2:57 PM
To: MOIMS-DAI List <moims-dai at mailman.ccsds.org
<mailto:moims-dai at mailman.ccsds.org> >
Subject: [Moims-dai] Reminder of Skype call tomorrow


Meeting: 10:00 Tuesday (Washington DC time), 1500 UK time, 1600 Paris time


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Draft agenda:


a.	Updated Draft Green Book





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