Re: [BioRDF] global uniqueness requirement of LSIDs and RDF

Hello John,

> 
> > How I've come to think about this is that some properties are 
intrinsic
> > to the type of record, for a person, perhaps their SSN if American, 
and
> > some are not, such as a person's age.  But even this becomes context
> > dependent if one wishes to track the state of the person once a year.
> 
> If I understand the uniqueness requirement of LSIDs, then a new LSID for
> "Michael Miller" must be created every year when the age property 
changes.

This is not quite how it is meant to work. You would only create a new 
LSID for Michael Miller each year if he was a data file and somehow his 
bytes changed :-)  In the case you describe Michael is more of an idea 
(sorry Michael!) with many facets, some that can be concretely represented 
as bytes (the bytes named) and some conceptual that can be described in 
metadata (that further describe the concept named) and  have no associated 
unique data (that is named) bytes. 

You could use an LSID (or any kind of URI) without any directly associated 
data bytes to represent Michael as a central concept. Then a metadata 
graph associated with this conceptual URI might tell you his date of 
birth, it might also contain links to LSIDs and other URIs that contain 
separate concrete representations of Michael - for example x-ray images, 
MRIs, his DNA sequence or results for other tests that have a binary 
representation and where it makes sense to uniquely name each as a 
discrete data item. These different representations may even be made 
available in different contexts/formats (e.g. images of differing size, 
resolution or binary format like png and gif) and each with its own LSID. 
Similarly if for some reason one of these images is changed later (say a 
better algorithm for sharpening), that new image instance could be made 
available as an LSID revision by incrementing the version area of the LSID 
name.

Kindest regards, Sean

--
Sean Martin
IBM Corp.