- From: Richard Wallis <richard.wallis@dataliberate.com>
- Date: Tue, 11 Apr 2017 15:30:07 +0100
- To: Giovanni Michetti <giovanni.michetti@ubc.ca>
- Cc: Jane Stevenson <Jane.Stevenson@jisc.ac.uk>, public-architypes <public-architypes@w3.org>
- Message-ID: <CAD47Kz6c+97XxxtH1isU1q0-ViPZD1wqU3SMC1xD-qyyzpgJzA@mail.gmail.com>
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>
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>
>>> 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>,
>>>> 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
>>>> Twitter: @rjw
>>>> On 11 April 2017 at 13:06, Giovanni Michetti <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>).
>>>> 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> 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>
>>>> 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>
>>>> 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> 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> 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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>>>> 0JA. T 0203 697 5800.
>>>>
>>>
>>>
>>
Received on Tuesday, 11 April 2017 14:30:44 UTC