[Esip-preserve] Possible Workaround for data identity non-uniqueness?

[Curt Tilmes]

On 10/13/10 08:56, Lynnes, Christopher S. (GSFC-6102) wrote:
> Is there perhaps a workaround where the reformatting agent simply
> asserts that they are equivalent?  That is, to add a metadata
> attribute that says, "this file is scientifically equivalent to this
> other file (e.g., identified by uuid)"?

Then we have to start tagging them with "Justification" and "Trust"
facts as well...

I see (at least) two use cases we are concerned with for scientific
equivalence:

1. The reformatting case.  I have data from some authoritative source,
    and I want to do a transformation that maintains what we are
    calling the "scientific equivalence class" (SEC).

    As you propose, we could use the "authoritative souce" UUID as a
    SEC identifier, and keep that with the transformed data.

    My justification could be that I validated my transformation
    process and assert that it does maintain that property.

2. The reproduction case. I have a granule and I want to repeat the
    processing in such a way that the resulting file is in the same SEC
    as the original.

    My justification could be that I have replicated the processing
    steps sufficiently to maintain that property.

    For example, consider "process on demand" where the original file
    was deleted, but the producer maintains sufficient provenance
    information to re-make a new file (with a distinct UUID) that
    should be in the same SEC.

    Or a web service transformation.  I can store a
    WCS/WFS/WMS/etc. REST URL with all the parameters used to produce a
    file.  If I call it with those parameters and you call it with
    identical parameters, we should get files in the same SEC.

Curt