On Mon, 2009-12-21 at 16:55 +0100, Martin Guetlein wrote:
> Hello All,
> 
> Tobias Girschick wrote:
> > Hello Nina,
> >
> > On Mon, 2009-12-21 at 14:21 +0200, Nina Jeliazkova wrote:
> > [...]
> >
> >>> RDF representations, structurally, contain much more (meta)information
> >>> about the objects they describe than ARFFs, so this piece of
> >>> information in the text/x-arff (the datatype of each feature) IMHO has
> >>> to be included in the RDF or at least - in order not to modify the RDF
> >>> standards we adopted in API 1.1 - we should use proper XSD datatypes
> >>> for every value. After all, its not 1^^double, 1^^string and
> >>> 1^^nominal is not the same and won't (shouldn't) be handled the same
> >>> way by a training algorithm.
> >>>
> >> Yes, especially for nominals, it would be better to introduce subclass
> >> of Feature, rather than using XSD types for denoting the types.  I might
> >> try to extend opentox.owl next days.
> >>
> >
> > This would be great. At the moment, classification is not possible as it
> > relies on a nominal target feature. Will this be reflected in the
> > text/x-arff, too?
> 
> Apart from feature value type I would like to have a "feature range"
> as well. This should be a property of a feature, which gives me all
> the possible feature values of a nominal feature (e.g. active,
> moderately-active, inactive). This is needed when validating a
> prediction algorithm.
> 
> What do you think?

The range of a feature can be described by its feature type. Imagine
something like <featureURI> <rdf:type> <xsd:possibleValuesare{1,2,3,4}>.
In XSD you can define you own datatypes and specify their range therein.
I'll try to write an example and post in on the list.

Best regards,
Pantelis

> 
> Best regards,
> Martin
> 
>