Hello Deirdre,
Thanks for the update. I will
include these discussions in the agenda for Wednesday TC meeting. Please find
my comments inline.
Thanks,
Eric
From: Lee, Deirdre
[mailto:Deirdre.Lee@deri.org]
Sent: Monday, March 29, 2010 10:14 AM
To: Eric Chan
Cc: marco pallot; Dragan, Laura
Subject: RDF ICOM model update
Hi,
Laura and I have been working on the RDF ICOM model. We have
updated the core ontology to match the changes we have discussed in the telcos.
We have also created two extensions to the core ontology to represent Access
Control and Metadata. Have a look here: http://resources.smile.deri.ie/icom/
A few points have arisen that we would like to discuss in
the telco on Wednesday are:
1.
Are AccessControlList, AccessControlEntry,
and Marker all root classes? i.e. they are not subclasses of Entity?
[Eric] Marker is a subclass of
Entity. AccesssControlList and AccessControlEntity are not entities.
2.
Is the description property only
associated with Scope, Space, and Folder,
or is it associated with all Entities?
[Eric] Description is a property
is not associated with all Entities/Artifacts. It is defined for some
subclasses of Artifact. If appropriate, we can make it an attribute of
Artifact.
3.
Should we change subCommunities to communities,
as in the Group class we have groups and not subGroups?
[Eric] Yes, it makes sense to
change the attribute name to either (communities, groups) or (subCommunities,
subGroups).
4.
Could we replace elements property in Space
and Folder to folders and artifacts
to distinguish?
[Eric] The elements property is polymorphic
at the superclass ArtifactContainer of Space and Folder. It allows us to
define elementOfArtifactContainer from which we can extend two sub-properties elementOfSpace
and elementOfFolder.
5.
Are the userCreatedOn/userModifiedOn
properties of Artifact the same as createdOn/modifiedOn
properties inherited from Entity?
[Eric] The userCreatedOn and
UserModifiedOn are different from the attribute in Entity. The
userCreatedOn reflects the time when the artifact is created (may be while the
client is offline) while createdOn is when the artifact is actually committed into
the repository. Similarly for the userModifiedOn time.
6.
Regarding the folder models, we would suggest to create
separate extension models for each type of folder, e.g. calendar, addressbook,
forum. Are each of these types modeled in more detail anywhere?
[Eric] Yes, we can define the specialized
folders sooner rather than later.
Other issues that we would like to discuss in detail are:
·
We are unsure what to do with TagApplication
and CategoryApplication. Can we discuss their use-cases some
more?
[Eric] They are needed only for
UML model. I have some explanation for their role in http://wiki.oasis-open.org/icom, “UML Links:
Category Application, Tag Application, and Bond Entity Relation” Section 9.0.
The UML model of entity
metadata in Figure 19 describes how a category, tag, or bond can be linked with
multiple entities. When the same metadata is linked to multiple entities, each
link between the metadata and an entity should be represented by a link object
to hold the attributions specific to the linked entity. ICOM UML model employs
CategoryApplication, TagApplication, and BondEntityRelation to represent,
respectively, the links from category, tag, and bond objects to entities.
Also…
- There are no counterparts for CategoryApplication,
TagApplication, and BondEntityRelation in the RDF model (these concepts
are syntactic mechanisms used only in UML model to represent the UML
links).
·
Similarly, we would like to suggest not using Bonds
for common use-cases. For example, if we make spaces hierarchical, there is no
need for Bonds in the workspace use-case. From the wiki, it suggests that Bonds
are included to address issues in translating the model to RDF. However the
model should be language independent. Also, we believe that the inclusion of
complex model structures may be a barrier to adoption. We are open to
discussion on this point.
[Eric] Let’s discuss this
issue.
Best regards and talk to you on Wednesday.
Deirdre and Laura
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Deirdre Lee
DERI
IDA BusinessPark, Lower Dangan,
Galway, Ireland
deirdre.lee@deri.org
skype: deirdrelee
+353 91 495336
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