- From: Giovanni Michetti <giovanni.michetti@ubc.ca>
- Date: Tue, 11 Apr 2017 16:54:51 +0200
- To: Richard Wallis <richard.wallis@dataliberate.com>
- CC: Jane Stevenson <Jane.Stevenson@jisc.ac.uk>, public-architypes <public-architypes@w3.org>
Hi Richard,
thank you very much--it's been very kind of you to prepare this long
explanation. It definitely clarifies the nature of Schema.org, and it
will help us working on it with the right perspective.
Giovanni
Il 11/04/2017 16:30, Richard Wallis ha scritto:
> Hi Giovanni,
>
> I know it can be sometimes difficult for folks to get their head around
> some of the idiosyncrasiessses of the Schema,org vocabulary.
>
> Part of the problem is that it is a vocabulary of types and properties
> to be used to describe things, not an ontology to define them. This is
> one of the reasons that they are described as Types and not Classes.
>
> For example, a photograph would be described using the Photograph type
> wherever it is. A photograph that is also an item within an archive
> however, has certain attributes that you would want to describe that are
> to do with it being in an archive (its archived-ness) - at least the
> archive it is partOf. To indicate this your markup would sow that it is
> both a Photograph and an ArchivedItem.
>
> The fact that certain types are subtypes of others, in Schema, is more
> to do with them sharing common properties than with an inheritance of
> concepts.
>
> ArchivedItem theoretically could be a direct subtype of Thing, but it is
> made a subtype of Intangible as direct subtypes of Thing are not
> encouraged in Schema. Using it to extend the description capabilities
> of a Photograph, Document, Product etc., does not infer that the thing
> itself is intangible, it is just using a descriptive type from the
> vocabulary.
>
> ~Richard.
>
>
>
>
> Richard Wallis
> Founder, Data Liberate
> http://dataliberate.com
> Linkedin: http://www.linkedin.com/in/richardwallis
> Twitter: @rjw
>
> On 11 April 2017 at 15:08, Giovanni Michetti <giovanni.michetti@ubc.ca
> <mailto:giovanni.michetti@ubc.ca>> wrote:
>
> I don't know, Jane. Somehow I get the vague idea behind this
> solution, anyway it doesn't seem just a problem of names--the
> definition reads "an item in an archival collection", so it is an
> item indeed. Since it is under Intangible, it is intangible too.
> Which leads to a further doubt--where should we put the tangible
> archival item?
>
> The overall picture is a bit confusing...
>
> Giovanni
>
>
>
>
> Il 11/04/2017 15:55, Jane Stevenson ha scritto:
>
> I think I do get ‘ArchivedItem’ now - I just didn’t for a while
> because I kept equating it to a real archival item.
>
> If I forget the name and just think of it as ‘X’ then I can see
> that it's just something to hang properties from that we think
> might be specific to archives. I think its kind of as simple as
> that….? But that’s why its probably best to drop ‘item’ - I
> know the name doesn't matter, but I think its confusing.
>
> Jane.
>
>
>
> On 11 Apr 2017, at 14:46, Giovanni Michetti
> <giovanni.michetti@ubc.ca <mailto:giovanni.michetti@ubc.ca>>
> wrote:
>
> Hi Richard,
>
> thank you for further explanation.
>
> I'm sorry, but I still don't get your point.
>
> ArchivedItem is "an item in an archival collection", so it
> is included in an archival collection by definition. Putting
> ArchiveCollection as a sub-class of ArchivedItem, means that
> ArchiveCollection is a type of ArchivedItem, which is not
> consistent with the definition of ArchiveCollection ("A
> collection and/or archive of physical or digital items").
>
> From your words, I understand that your choice was driven
> by the need for specific properties. If that's the case, I
> wonder why we can't simply extend the properties of Thing,
> or find anyway some other solution.
>
> Giovanni
>
>
>
> Il 11/04/2017 14:45, Richard Wallis ha scritto:
>
> Hi Giovanni,
> Your view of the generic nature of ArchiveCollection
> (/Therefore, a fonds, a series, a subseries, a
> collection, a set of sparsed objects may all be subsumed
> under ArchiveCollection according to the its
> definition/.) is what I had in mind when I made the
> original proposal.
> Both Jane and you express confusion as to why
> ArchiveCollection is a sub-class of ArchivedItem, which
> is initially understandable. The reason I proposed it
> that way is to make pragmatic use of the way Schema.org
> is constructed.
> ArchivedItem
> <http://archive.sdo-archive.appspot.com/ArchivedItem
> <http://archive.sdo-archive.appspot.com/ArchivedItem>>,
> when added as an additionalType of any other Thing
> (CreativeWork, Product, whatever) effectively makes
> available properties to describe attributes of its
> membership in an archive (provenance, accessAndUse,
> itemCondition, location, transfer, etc.). If the Type
> of Thing is unknown ArchivedItem could potentially be
> used as the only Schema Type.
> When looking to describe an ArchiveCollection, the
> majority of those properties would also be of use in its
> description. To achieve this the proposal could have
> either individually added these properties to
> ArchivedCollction or, as I proposed, just make it a
> subtype of ArchiveCollection.
> ~Richard.
> Richard Wallis
> Founder, Data Liberate
> http://dataliberate.com
> Linkedin: http://www.linkedin.com/in/richardwallis
> <http://www.linkedin.com/in/richardwallis>
> Twitter: @rjw
> On 11 April 2017 at 13:06, Giovanni Michetti
> <giovanni.michetti@ubc.ca
> <mailto:giovanni.michetti@ubc.ca>
> <mailto:giovanni.michetti@ubc.ca
> <mailto:giovanni.michetti@ubc.ca>>> wrote:
> Hi Jane,
> I would stick to the definition of
> ArchiveCollection, which is "A
> collection and/or archive of physical or digital
> items."
>
> (http://archive.sdo-archive.appspot.com/ArchiveCollection <http://archive.sdo-archive.appspot.com/ArchiveCollection>
>
> <http://archive.sdo-archive.appspot.com/ArchiveCollection <http://archive.sdo-archive.appspot.com/ArchiveCollection>>).
> The Archival Extension doesn't define what an
> archive is (as a set
> of objects--an archive is either an institution or
> an organization,
> according to the definition of Archive). However,
> it is quite clear
> that the definition of ArchiveCollection intends to
> cover any
> aggregation of items, that is, the term 'archive'
> in the definition
> is used in a very generic sense. Therefore, a
> fonds, a series, a
> subseries, a collection, a set of sparsed objects
> may all be
> subsumed under ArchiveCollection according to the
> its definition.
> Using a single class to identify any type of
> aggregations (including
> no aggregation at all) is consistent with the most
> relevant archival
> standards: ISAD uses "Unit of description" and EAD
> uses "Component".
> Recently, ICA proposed a draft model (RiC) where
> they identified two
> classes, Record and RecordSet (along with
> RecordComponent), which is
> a bit different from the other models, yet is based
> on a single
> class identifying any aggregation--that is, no need
> for fonds,
> series, etc.
> We can discuss whether we need to distinguish
> between the single
> item and its aggregations, or it is better to just
> stick to a
> simpler model, ie "Component" like in EAD. However,
> going to your
> questions, I don't see any problem in considering
> both your examples
> as being instantiated under ArchiveCollection. The
> same for the
> properties.
> I don't understand very well why ArchiveCollection
> is a sub-class of
> ArchivedItem in the Extension, so I share your doubts.
> As I wrote in some earlier message, I have many
> doubts about this
> model. For this reason, I started investigating it
> further with some
> colleagues of InterPARES Trust, in order to provide
> some systematic
> comments on the Archival Extension. My aim is to
> share the comments
> in a month.
> Regards
> Giovanni
> Il 11/04/2017 11:16, Jane Stevenson ha scritto:
> Hi there,
> I had a huge email written as I was working
> this out, but I’ve
> tried my best to distill it down to one
> essential question…..
> There is a type ‘ArchiveCollection', which has
> ’super types’ of
> CreativeWork’ and ‘ArchivedItem’ with
> properties we can use to
> describe our thing(s).
> To take an example, let’s say I wanted to have
> schema.org <http://schema.org>
> <http://schema.org> markup attached to:
> A collection or ‘top level’ description:
> https://archiveshub.jisc.ac.uk/data/gb2607-ec/1-12
> <https://archiveshub.jisc.ac.uk/data/gb2607-ec/1-12>
>
> <https://archiveshub.jisc.ac.uk/data/gb2607-ec/1-12
> <https://archiveshub.jisc.ac.uk/data/gb2607-ec/1-12>>
> A lower level description:
> https://archiveshub.jisc.ac.uk/data/gb2607-ec/1-12/ec/7
> <https://archiveshub.jisc.ac.uk/data/gb2607-ec/1-12/ec/7>
>
> <https://archiveshub.jisc.ac.uk/data/gb2607-ec/1-12/ec/7
> <https://archiveshub.jisc.ac.uk/data/gb2607-ec/1-12/ec/7>>
> All I know about these are that one is ‘top
> level’ so that there
> are no parent levels above it, but there may be
> child levels.
> The other is lower level, so it has at least
> one parent level.
> Can I just treat the lower level ’thing(s)' as
> type=ArchiveCollection? So, I can I use the
> properties from
> CreativeWork and ArchivedItem for both the top
> level and lower
> level group of stuff?
> I don’t want to distinguish between collection
> and item actually
> within the archive; I just want to apply
> schema.org <http://schema.org>
> <http://schema.org> markup using the
> appropriate types and
> associated properties.
> Richard defined Collection:
> “ArchiveCollection: The
> collection/grouping/assemblage of
> archived items. Descriptive properties
> reference the collection
> as a whole.”
> I want to separate this out from what archivist
> thing of as an
> archive collection, and treat it simply as a
> ‘group of things’
> or even just one thing if that represents a
> stand-alone
> collection. Is this correct?
> The archive.schema.org
> <http://archive.schema.org> <http://archive.schema.org>
> defines
> ‘ArchivedItem’ as ‘an item in an archive
> collection’. But I
> thought it was a ‘type' that is applied to
> ArchiveCollection? I
> didn’t think it actually related to ‘item’
> meaning a single thing.
> I think there is some confusion in the
> documentation between the
> term ‘ArchivedItem’, which I understand to be a
> type that can be
> applied to an ArchiveCollection, with properties of
> ‘archive-ness’, and an actual item in a
> collection (and we
> don’t usually describe single items anyway). It
> maybe doesn’t
> help that the properties within ArchivedItem
> are ‘item’ - e.g.
> itemDescription, itemLocation, itemProvenance.
> Can I see them as
> archiveunitDescription, archiveunitLocation,
> archiveunitProvenance.
> NB - that’s why in EAD we use ‘unit’ and not
> anything like
> ‘item’ - because we can only know that it is a
> unit within a whole.
> cheers
> Jane
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Received on Tuesday, 11 April 2017 14:53:16 UTC