- From: Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
- Date: Mon, 14 Nov 2011 22:23:44 +0000
- To: public-prov-wg@w3.org
PROV-ISSUE-150: question on formal semantics of role in wasGeneratedBy relation [Formal Semantics]
http://www.w3.org/2011/prov/track/issues/150
Raised by: Stephan Zednik
On product: Formal Semantics
I am slightly confused about the formal semantics of the role qualifier in a wasGeneratedBy relation.
from http://www.w3.org/TR/prov-dm/#prov-dm-overview
"Qualifiers can be associated to relations, namely use and wasGeneratedBy, in order to further characterize their nature. Role is a pre-defined qualifier."
and from http://www.w3.org/TR/prov-dm/#expression-qualifier
"The PROV data model introduces the qualifier role in the PROV-DM namespace to denote the function of a characterized thing with respect to an activity, in the context of a use/generation/control relation. The value associated with a role attribute must be conformant with Literal."
I have sensed confusion in the prov-o discussions as to whether the role in a generation is played by the process execution or the generated entity. Can a generated entity play a role in the activity that generates it? Can a process execution play a role, that is be the characterized thing that has a function in an activity? Does the definition of role need to be changed?
I know discussion of role has taken up a lot of time, this sure has turned out to be a tricky issue, but I think getting qualifiers right is worth it.
There is an example in the primer, http://dvcs.w3.org/hg/prov/raw-file/default/primer/Primer.html#roles-1, but I am not sure if it is representative of the intent for role on a generation relation.
ex1:aggregated
prov:hadQualifiedGeneration [ a prov:Generation ;
prov:hadQualifiedEntity ex1:aggregate1 ;
prov:hadRole ex1:aggregatedData
] .
--Stephan
Received on Monday, 14 November 2011 22:23:49 UTC