RE: [xri] [Glossary] Definition of "Resource" and "Attribute" (lo ng)

[Drummond Reed <Drummond.Reed@onename.com>]

Mike (and Gabe before him): good stuff. The main reason I sent that opening
salvo was to help folks realize how large an impact to the whole effort even
small issues with these core terms have.

The second reason is that, while it might seem like the term "attribute" may
not be that important, in my experience with both XNS and Liberty, it ends
out being very important - almost as important as "resource". Being able to
unambiguously and persistently reference an attribute in the context of a
specific resource is critical when it comes to security, digital identity,
DRM, and many other applications of XRIs.

That said, I agree with you, Gabe, and Bernard that we should just stick
with the URI spec definition of resource as "anything that has identity" and
not try to define it further. It's not worth splitting hairs over whether
simple attributes actually have identity outside of the resource that they
describe.

I think your definition of attribute as " data, metadata or other resources
associated with a resource" is pretty close to the mark but the words
"associated with a resource" don't quite fully distinguish the two things I
think are most important about attributes vs. resources:

1) Attributes are always relative, i.e., they only exist in the context of a
specific resource, and
2) A special kind of attribute - an identifier - exists for the special
purpose of forming an association with ANOTHER resource (that's our
definition of identifier). 

To capture these two nuances, here's a modification to your proposed
definition of "attribute":

	Data, metadata or other resources that describe a specific resource.
Attributes are always relative to the resource they describe. Identifiers
are an attribute of one resource whose purpose is to form an association
with another resource.

How's that work?

=Drummond 

 

 

-----Original Message-----
From: Lindelsee, Mike [mailto:mlindels@visa.com]
Sent: Thursday, February 27, 2003 11:41 AM
To: 'xri@lists.oasis-open.org'
Subject: FW: [xri] [Glossary] Definition of "Resource" and "Attribute" (lo
ng)

Wow, you've spent a lot of time thinking about this and writing it down,
Drummond.  While your analysis is interesting, it seems to go too far.
Although I completely agree that we need to come to grips with the terms
"resource" and "attribute," I believe strongly that simpler definitions will
suffice.  Not only will simplicity help others understand what we mean, it
will layer fewer semantics onto the XRI specifications.  I think that it is
very important for XRI's to identify "things" (I'm avoiding any possibly
controversial words for the time being) and for applications to be able to
layer semantics onto the identification -- the XRI specs should create a few
semantic layers as is possible.

That being said, I do believe that it is important to be able to distinguish
between "resources" that are containers, or groupings, of other resources
and individual resources.  For instance, some applications using XRI's might
define resources to be the groupings and "attributes" to be inidivdual
resources.  While this might work for some applications, I can also think of
applications where such a distinction would not be useful or necessary. 

As a proposal, I am a fan of keeping the current definition of resource
(from RFC 2396) and defining attribute as something like:

  data, metadata or other resources associated with a resource

Although as I think about it further, I'm not even convinced that we
necessarily need to define attribute.  We might use the term, but I'm not at
all sure that it will need to make its way into the actual specification
(where everything might just be defined in terms of resources).

Anyway, that was my $.02 and I'm happy to hear what others have to say.

Mike