Re: metadata about relationships

On Wed, Feb 22, 2012 at 8:05 AM, Will Norris <will@willnorris.com> wrote:

> (2nd attempt at sending, hopefully not a duplicate)
>
> In general, schema.org (or microdata in general?) seems to lack the
> ability to specify metadata for the relationship between items.  I'm
> curious if there is a general pattern for how this data should be modeled.
>

I think the simplest way to do this is to create a new type for the
relationship itself.  For example, rather than just have a price attribute,
Product points to an Offer <http://schema.org/Offer> object that has
additional information like availability window.


> First a concrete example.  The Person type describes an individual person,
> and the EducationalOrganization type describes an actual education
> institution.  The 'alumniOf' property defines the existence of a
> relationship between a Person and an EducationalOrganization, but there is
> nowhere to provide additional metadata about that relationship.  Things
> like graduation year, field of study, etc.  Similarly for work information
> defined by either 'worksFor' or the more general 'affiliation'.  I know
> there has been discussion of including a CV schema which would likely
> address these specific examples, but this seems to be a more general
> problem with RDF style triples.  There's plenty of space to exhaustively
> define the subject and object, but no room to provide metadata around the
> predicate.  How is this type of thing handled in general?
>

This can be done in the same way as Offer with new types that describe a
specific kind of relationship such as EmploymentTenure, Marriage,
Performance, etc.  However, this kind of mediation comes at an
implementation complexity cost, which is why I believe it was used
sparingly in the initial release schema.org.  However, if enough use cases
require this additional data for a specific , I think the case could be
made for proposing changes to the schema.


> And more specifically, how should it be handled in the above examples?  We
> include this metadata in Google+ profiles, and are able to include it
> cleanly in Portable Contacts, but I don't see how to represent it in
> schema.org.
>
> -will
>