Over the last few weeks we’ve been testing our initial cut at an EAD-to-RDF transform against a range of data that extends beyond EAD documents prepared using the Hub data entry template to documents created using other tools – and varying somewhat in terms of the markup conventions used.

In the course of that, I’ve been pondering some of the choices we made in the model I described here and here, and we decided to make a couple of changes (one very minor and the second still relatively so, I think):

• Archival Resource: We’ve changed the name of the class we were calling “Unit of Description” to “Archival Resource”. I think “Unit of Description” was problematic for two reasons. First, it was ambiguous, because it could be interpreted either as the unit (of archival material) being described (which is what was intended) or as a unit/part of the archival description (which is not what was intended). Second, I adopted it from the ISAD(G) standard, where the context is one in which the archival resources are considered to be the primary things being described. I’m less sure the label works in the “linked data” context where we’re providing statements, and sets of statements (descriptions), “about” not just the archival materials, but many other things. In this context, everything that is described (people, concepts, places, etc) might be seen, in some sense, a “unit of description”, and so using that label for one subset of them seems inappropriate. That left us with finding a suitable alternative, a generic term that covers archival material in general, at any level of description (fonds, collection, item etc), and “archival resource” seemed like a reasonable fit.
• Origination as Concept: When I first sketched out the model, I raised some questions, including (as “question 3” in that post) whether it was useful/necessary to model the origination of the archival resource as a pair of concept and agent, following the pattern used for the <controlaccess> terms. Having experimented with that approach, we’ve decided it introduces unnecessary complexity and we’ve fallen back on treating <origination> as a simple relation between archival resource and agent. The use of concept and agent is retained for the <controlaccess> case, where names are typically drawn from an “authority file”, as it allows us to maintain the distinction between a conceptualisation of the agent (as reflected by the authority record/entry) and the agent itself (a distinction which is also made in the model underpinning datasets such as VIAF, which we will be making links to).

The revised model is summarised in the following diagram (an amended version of Figure 3 from the earlier post):

Amended data model for EAD

i.e. an Archival Resource and a Biographical History are now related directly to an Agent.

Below is a draft list of human-readable definitions for the classes in the model. Some are simply references to classes provided by existing vocabularies like Dublin Core, FOAF, event vocabularies:

Finding Aid

A document describing an archival resource.
Subclass of: bibo:Document, foaf:Document

EAD

A document conforming to the Encoded Archival Description standard.
Subclass of: bibo:Document, foaf:Document

Biographical History

A narrative or chronology that places the archival materials in context by providing information about their creator(s). A finding aid may contain several such narratives or chronologies pertaining to different archival materials and their creators.
Subclass of: bibo:DocumentPart, (bibo:Document), foaf:Document

Repository

An institution or agency responsible for providing access to archival materials.
Subclass of: foaf:Organization, (foaf:Agent), dcterms:Agent

Place

= wgs84_pos:SpatialThing

Postcode Unit

= ospc:PostcodeUnit

Archival Resource

Recorded information in any form or medium, created or received and maintained, by an organization or person(s) in the transaction of business or the conduct of affairs, and maintained for its long-term research value. An archival resource may be an individual item, such as a letter or photograph, or (more commonly) some aggregation of such items managed and described as a unit.

Level

An indicator of the part of an archival collection constituted by an archival resource, whether it is the whole collection or a sub-section of it.
Subclass of: skos:Concept

Language

= lvont:Language

Extent

The size of an archival resource.
Subclass of: dcterms:SizeOrDuration

Temporal Entity

= time:TemporalEntity

Creation

An event that resulted in the creation or accumulation of an archival resource.
Subclass of: event:Event, lode:Event

Concept

= skos:Concept

Concept Scheme

= skos:ConceptScheme

Agent

= foaf:Agent, dcterms:Agent

Person

= foaf:Person, (foaf:Agent), dcterms:Agent

Family

A group of people affiliated by consanguinity, affinity, or co-residence.
Subclass of: foaf:Group, (foaf:Agent), dcterms:Agent

Organisation

= foaf:Organization, (foaf:Agent), dcterms:Agent

Genre or Form

A category of archival material, defined either by style or technique of intellectual content, order of information or object function, or physical characteristics.
Subclass of: skos:Concept

Function

A sphere of activity or process.
Subclass of: skos:Concept

Birth

= bio:Birth, (bio:IndividualEvent), (bio:Event),
(event:Event), (lode:Event)

Death

= bio:Death, (bio:IndividualEvent), (bio:Event),
(event:Event), (lode:Event)

Object

= foaf:Document, bibo:Document

Book

= bibo:Book, (bibo:Document), (foaf:Document)