[foaf-dev] [foaf-protocols] revisiting FOAF project goals

Matthew Rowe m.rowe at dcs.shef.ac.uk
Wed Jun 24 14:37:39 CEST 2009


On 24 Jun 2009, at 12:40, Melvin Carvalho wrote:

> On Wed, Jun 24, 2009 at 1:33 PM, Matthew Rowe<m.rowe at dcs.shef.ac.uk>  
> wrote:
>> Hello
>>
>> I concur with what Dave has said here, particularly regarding the  
>> need
>> to explicitly define topics of relationships and associated trust
>> values.
>>
>> I think that the latter issue (assigning trust values to
>> relationships) as this appears to becoming especially important now
>> that work within the Semantic Web community is moving towards trust.
>
> This is something I'd also like, to see as trust and reputation
> infrastructure (eg for relationships) could be a valuable long term
> goal, built of the foundation that FOAF provides.
>
> However, I'm not sure how weight to an edge in RDF, without using a
> wrapper around the subject object pair (predicate is assumed) or
> reification, though i understand reification is not a popular option.
>
> Perhaps named graphs can help, or maybe storing an extra field in a DB
> for the weighting?

Yeh this is something I have been puzzled by aswell. Olaf Hartig's  
paper on "Querying trust in RDF data with rSPARQL" [1] details that  
RDF graphs can be trust weighted, and expresses individual statements  
within the RDF graph as having trust values (ranging from 0-1).  
However, the paper does not explicitly say how trust values would be  
stored (ie. what the semantics would be for expressing a trust value).  
As you suggested it appears that the db contains an associated trust  
value with a given triple. I assume that in terms of assigning trust  
values to relationships, trust values would be assigned to the  
relationship triple:

(<#Alice> foaf:knows <#Bob>) 0.9

I am really unsure how this would be described.


[1] - http://www.eswc2009.org/program-menu/accepted-papers/104-olaf-hartig-querying-trust-in-rdf-data-with-tsparql



>
>
>>
>>
>>
>> On 24 Jun 2009, at 03:31, Dave Brondsema wrote:
>>
>>> I initially became interested in FOAF when I found it as a
>>> decentralized
>>> way to declare relationships, especially since some social network
>>> providers already exported FOAF data.  That was several years ago
>>> when I
>>> was working on Konfidi, a senior project at school:  http://konfidi.org/
>>> I still put some time into working on it and want Konfidi to become
>>> truly useful for filtering email and blog spam, and more.  Its
>>> progress
>>> has been pretty slow though, since it's just one of many side  
>>> projects
>>> for me.
>>>
>>> For Konfidi, I've ended up deciding that using existing foaf:knows
>>> relations is great, but we also have our own Relationship class so  
>>> we
>>> can add topics and trust amounts to the relationship.
>>>
>>> For practical purposes, I'm mainly interested in the major providers
>>> that produce FOAF data, and those that have xfn microformat data.
>>> While
>>> many of us write our own FOAF files, the public can't be expected to
>>> do
>>> so, nor even know what FOAF is really.  One part of Konfidi will  
>>> be a
>>> webapp where you can log in with openid and declare some of your
>>> relationships.  That would create the RDF for them, but all they'd
>>> know
>>> is they're using the Konfidi system, nothing about FOAF or RDF.
>>>
>>> --
>>> Dave Brondsema : dave at brondsema.net
>>> http://www.brondsema.net : personal
>>> http://www.splike.com : programming
>>>               <><
>>>
>>> _______________________________________________
>>> foaf-protocols mailing list
>>> foaf-protocols at lists.foaf-project.org
>>> http://lists.foaf-project.org/mailman/listinfo/foaf-protocols
>>
>>
>> Matthew Rowe, MEng
>> PhD Student
>> OAK Group
>> Department of Computer Science
>> University of Sheffield
>> m.rowe at dcs.shef.ac.uk
>>
>> _______________________________________________
>> foaf-protocols mailing list
>> foaf-protocols at lists.foaf-project.org
>> http://lists.foaf-project.org/mailman/listinfo/foaf-protocols
>>


Matthew Rowe, MEng
PhD Student
OAK Group
Department of Computer Science
University of Sheffield
m.rowe at dcs.shef.ac.uk



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