[Rdap] What makes an 'Archive Quality' Digital Object?
Joe Hourcle
oneiros at grace.nascom.nasa.gov
Wed Apr 27 13:53:12 EDT 2011
On Wed, 27 Apr 2011, Michael J. Giarlo wrote:
> On 04/26/2011 03:30 PM, Joe Hourcle wrote:
>>
>>>
>>> The first bit I have trouble wrapping my mind around is that the notion
>>> of archival quality is binary, that an object can be of archival quality
>>> or not.
>>
>> Maybe I should be asking the opposite --
>>
>> What would make a digital object *not* of archival quality?
>
> I'd respond the same. :) I couldn't confidently say whether an object
> is archival or not archival w/o a lot more context along the dimensions
> I mentioned (use, file formats, retention period, etc.), and even then I
> would be inclined not to say it's archival or not but rather give a
> qualified judgment on *how* likely I think that object will be around in
> N years.
Perhaps we need to treat it more like IT security ...
A password of (x) length and (y) complexity is expected
to be good for about (z) time ... but as new attacks are
found, (z) might decrease.
... and come up with recommendations for different time spans (if you want
it to last (x) time, you should ...) or different levels of effort (if you
only do (y), it'll likely be unreadable within (z) time.)
[trimmed]
> I guess this might be a good place to bring up what may be a related
> technology:
[trimmed]
> """ -- http://en.wikipedia.org/wiki/Data_Format_Description_Language
>
> I haven't had the occasion to use DFDL -- and I tend to shy away from
> huge blobs of XML and XML Schema -- but it could have some promise in
> this area. Has anyone else used DFDL or thought about it in the context
> Joe brings up?
I hadn't seen that one. There's been a discussion by the SPASE group [1]
about the need for documenting ASCII files, and I had brought up DSPL:
http://code.google.com/apis/publicdata/
They had the problem though that it seemed tightly tied to the individual
file to be processed, rather than having it link to a collection of files,
or have the data file link back to the description (or more than one
description, in different languages, but then we start getting into
the realm of self-documenting formats)
And they seemed more geared towards ASCII, while it sounds like DFDL might
be able to describe more complex stuff, like FITS & VOTable.
(when I was working on catalogs, I started on a parser to use ExtJS to
display the contents of VOTable, but dropped it when they kept giving
different responses regarding the change to ExtJS's license from BSD to
LGPL to GPL, and my unwillingness to spend 2+ years going through NASA's
legal council ... and there was some concerns about section 508 support)
[1] Space Physics Archive Search & Extract; http://www.spase-group.org/
-Joe
(yes, yes, the not reading e-mail thing isn't working).
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