What do we mean by GUID?

Nozomi Ytow nozomi at BIOL.TSUKUBA.AC.JP
Thu Oct 13 01:39:53 CEST 2005

Matt Jones wrote:

> The term GUID is one we started using in SEEK when looking for a
> solution to the identity and resolution problems that we saw looming for
> the Taxonomic COncept Standard.  Dave Thau's presentation on this
> (linked on the GUID wiki) defines this pretty well and explores the issues.

Here we see a tipical trouble with identifier and identity.  Do you
mean identity of an object (a unique thing, so we don't need
identifier because it is the thing) or equivalence of data (there can
be multiple data objects having the same value)?  Where we need GUID
we can't rely on identity, in my understanding.

> "globally unique" means simply that an identifier that is issued can
> only have one valid interpretation across all possible systems.

What do you mean by valid?  Suppose a data object in data provider's
database.  A GBIF portal has its copy when last a user accessed to the
data object.  The data provider changes its contents for some reason
afther the last access through the GBIF portal.  What is the
valid interpretation of these data objects?  Tha provider's one?

> Regardless of the mechanism used to resolve the identifier, the object
> that the id 'identifies' will be bit-for-bit identical.

So you mean equivalence, not identity.  If it is bit-for-bit
equivalence, why do you need GUID?  The contents IS the GUID
you defined.

> There are some tricky issues
> dealing with granularity of the identifier for digital data (does the
> identifier point at a tuple in an entity, or at a whole entity, or at
> multiple entities).

Do you mean your bit-for-bit GUID requires scope disamibugater also?
Isn't it assigned to a data object, i.e. unit to be handled as a

It may be better to use other words such as globally disambiguateor
or distinguisher, because we do not mean identity by identifier.


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