Re: License unknown

The reason I labeled it tried-to-determine-license is that that way the
assertion remains true. If the predicate is whether we *have* determined
license then the assertion needs to be retracted when we do. When possible
we try to make statements that remain true.

When probing for a license, first check dc:license, and if it is absent,
check :tried-to-determine-license.

In user interfaces there's no reason to show both. It's perfectly
reasonable to use these properties to decide whether to show "License:
Unknown"

-Alan


On Wed, Jun 18, 2014 at 8:46 AM, M. Scott Marshall <mscottmarshall@gmail.com
> wrote:

> Just a slight tweak to Alan's suggestion (thanks Alan):
> :determined-license "true"^xsd:Boolean
>
> -Scott
>
> On Wed, Jun 18, 2014 at 2:36 PM, Alan Ruttenberg
> <alanruttenberg@gmail.com> wrote:
> > I concur. This is clear from the semantics of OWL. Understand the
> difference
> > between integrity constraints and OWL assertions.
> >
> > If you want to say that there was an attempt to find a license and that
> it
> > couldn't be found, say that. You could do so as an annotation on the
> axiom,
> > or as a distinct property e.g.
> > :tried-to-determine-license "true"^xsd:Boolean
> >
> > This can remain true, as a historical fact, even after a license is
> found.
> >
> > For more about integrity constraints see
> http://clarkparsia.com/pellet/icv/
> >
> > -Alan
> >
> >
> >
> > On Monday, June 16, 2014, Jerven Bolleman <me@jerven.eu> wrote:
> >>
> >> Hi Alasdair,
> >>
> >> I think you are closing the world the wrong way. Both in limiting a
> >> dataset to have one license and secondly by having an "unknown" string
> >> to encode that you don't know something.
> >> Instead of using "unknown" you should use a blank node.
> >>
> >> cc:CC0 owl:sameAs "unknown"
> >>
> >> is plain wrong and can't be inferred
> >>
> >> cc:CC0 owl:sameAs _:1
> >>
> >> is fine and a nice way of allowing dataset from different sources
> >> descriptions to be combined and give more information.
> >>
> >> If you don't want a blank node, make a local node instead.
> >> cc:CC0 owl:sameAs <./#license>
> >>
> >> I implore you to change your mind on this. Choose semantics over special
> >> values!
> >>
> >> Regards,
> >> Jerven
> >>
> >>
> >> On Mon, Jun 16, 2014 at 5:44 PM, Gray, Alasdair J G <
> A.J.G.Gray@hw.ac.uk>
> >> wrote:
> >> > Hi Jerven,
> >> >
> >> > We are trying to ensure that a license is provided for a dataset, and
> >> > that
> >> > only one license is provided. (We are closing the world in certain
> >> > areas.)
> >> >
> >> > Our proposed solution is written up at
> >> > https://github.com/joejimbo/HCLSDatasetDescriptions/issues/65
> >> >
> >> > Alasdair
> >> >
> >> > On 2 Jun 2014, at 16:47, Jerven Bolleman <me@jerven.eu> wrote:
> >> >
> >> > Hi Alasdair,
> >> >
> >> > It is good practice in my opinion to not state unknown facts. If you
> >> > want to state there should be a license but you don't know it I think
> >> > some owl modelling is called for.
> >> >
> >> > e.g. roughly like this.
> >> >
> >> > dusty_data a dct:Dataset .
> >> > dusty_data rdfs:subClassOf [ a owl:Restriction ;
> >> >                                            owl:onProperty dct:license
> ;
> >> >                                            owl:minCardinality 1 ]
> >> >
> >> >
> >> > If anyone does something like
> >> >
> >> > dusty_data a dct:dataset .
> >> > dusty_data dct:license bad_example:unknown_license .
> >> >
> >> > and then someone figures out it has a license .
> >> >
> >> > dusty_data a dct:Dataset .
> >> > dusty_data dct:license cc:zero .
> >> >
> >> > And puts all those triples into one store/ontology then queries will
> >> > start to return wrong data.
> >> >
> >> > SELECT ?datasetWithALicense
> >> > WHERE {
> >> > ?datasetWithALicense dct:license ?license .
> >> > }
> >> >
> >> > Will give 2 bindings for ?dataset and ?license one of them being wrong
> >> > now.
> >> >
> >> > If you ask the same question depending on the better modelling then
> >> > you get the correct answer in both cases.
> >> >
> >> > SELECT ?datasetWIthoutLicense
> >> > WHERE {
> >> > ?datasetWIthoutLicense a dct;Dataset .
> >> > MINUS ( ?datasetWIthoutLicense dct:license ?license )
> >> > }
> >> >
> >> > SELECT ?datasetWIthALicense
> >> > WHERE {
> >> > ?datasetWIthALicense a dct;Dataset .
> >> > ?datasetWIthALicense dct:license ?license .
> >> > }
> >> >
> >> > Both give the expected results.
> >> >
> >> >
> >> > In general in RDF just state what you know and describe what you don't
> >> > know.
> >> >
> >> > Regards,
> >> > Jerven
> >> >
> >> > On Mon, Jun 2, 2014 at 5:25 PM, Gray, Alasdair J G <
> A.J.G.Gray@hw.ac.uk>
> >> > wrote:
> >> >
> >> > Hi,
> >> >
> >> > I am working to help shape the Healthcare and Life Sciences community
> >> > profile for describing datasets, current version available from [1]
> >> >
> >> > One of our goals is that there is a minimal set of properties that are
> >> > available for all datasets, and we would like these properties to
> >> > include
> >> > the license. However we have the problem that for several legacy
> >> > datasets
> >> > the license is simply unknown. Does anyone know of a resource that can
> >> > be
> >> > used to represent that the license is unknown as the value of a
> >> > dcterms:license predicate?
> >> >
> >> > Thanks
> >> >
> >> > Alasdair
> >> >
> >> > [1] https://github.com/joejimbo/HCLSDatasetDescriptions
> >> >
> >> > Alasdair J G Gray
> >> > Lecturer in Computer Science, Heriot-Watt University, UK.
> >> > Email: A.J.G.Gray@hw.ac.uk
> >> > Web: MailScanner has detected a possible fraud attempt from
> >> > "www.macs.hw.ac.uk" claiming to be http://www.alasdairjggray.co.uk
> >> > ORCID: http://orcid.org/0000-0002-5711-4872
> >> > Telephone: +44 131 451 3429
> >> > Twitter: @gray_alasdair
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > ________________________________
> >> >
> >> > Sunday Times Scottish University of the Year 2011-2013
> >> > Top in the UK for student experience
> >> > Fourth university in the UK and top in Scotland (National Student
> Survey
> >> > 2012)
> >> >
> >> > We invite research leaders and ambitious early career researchers to
> >> > join us
> >> > in leading and driving research in key inter-disciplinary themes.
> Please
> >> > see
> >> > www.hw.ac.uk/researchleaders for further information and how to
> apply.
> >> >
> >> > Heriot-Watt University is a Scottish charity registered under charity
> >> > number
> >> > SC000278.
> >> >
> >> >
> >> >
> >> >
> >> > --
> >> > Jerven Bolleman
> >> > me@jerven.eu
> >> >
> >> >
> >> > Alasdair J G Gray
> >> > Lecturer in Computer Science, Heriot-Watt University, UK.
> >> > Email: A.J.G.Gray@hw.ac.uk
> >> > Web: MailScanner has detected a possible fraud attempt from
> >> > "www.macs.hw.ac.uk" claiming to be http://www.alasdairjggray.co.uk
> >> > ORCID: http://orcid.org/0000-0002-5711-4872
> >> > Telephone: +44 131 451 3429
> >> > Twitter: @gray_alasdair
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > ________________________________
> >> >
> >> > Sunday Times Scottish University of the Year 2011-2013
> >> > Top in the UK for student experience
> >> > Fourth university in the UK and top in Scotland (National Student
> Survey
> >> > 2012)
> >> >
> >> > We invite research leaders and ambitious early career researchers to
> >> > join us
> >> > in leading and driving research in key inter-disciplinary themes.
> Please
> >> > see
> >> > www.hw.ac.uk/researchleaders for further information and how to
> apply.
> >> >
> >> > Heriot-Watt University is a Scottish charity registered under charity
> >> > number
> >> > SC000278.
> >>
> >>
> >>
> >> --
> >> Jerven Bolleman
> >> me@jerven.eu
> >>
>
> --
> M. Scott Marshall, PhD
> MAASTRO clinic, http://www.maastro.nl/en/1/
> http://eurecaproject.eu/
> http://semantic-dicom.org/
> https://plus.google.com/u/0/114642613065018821852/posts
> http://www.linkedin.com/pub/m-scott-marshall/5/464/a22
>