Status of this Document
- Draft for public review (28 April 2014)
- Please send general comments about this document to the listserv bibframe@loc.gov or via email to bfcomments@loc.gov.
- To the extent possible under law, the Library of Congress has waived all copyright and related or neighboring rights to this work.
Changes in this version (28 April 2014)
- An example of a BIBFRAME Authority represented as a reusable resource is provided (figure 1A). In the previous draft all BIBFRAME Authorities were represented as blank nodes.
- New section 4.2 "Role Expressed as String."
Table of Contents
1. Introduction
A BIBFRAME Authority is a resource representing a person, family, organization, jurisdiction, meeting, place, topic, or temporal expression associated with a BIBFRAME Work, Instance, or Annotation.
BIBFRAME Authorities are not designed to replace or compete with existing authorities but rather to provide a common abstraction layer, or wrapper, around them. Thus “BIBFRAME Authority” is distinguished from “authority” and the latter term (no qualifying “BIBFRAME”, and lower-case ‘a’) is used in this specification to refer to an existing authority, not to a BIBFRAME Authority.
For discussion of the approach taken by this specification see BIBFRAME discussion paper On BIBFRAME Authority.
2. Examples
The following example shows a BIBFRAME Work, with a title and a link to a creator. The creator is expressed as a BIBFRAME Authority, shown in the second half of the example.
<bf:Work>
<bf:title>Collage</bf:title>
<bf:creator rdf:nodeID=”bnode-x24z100”/>
</bf:Work>
<!-- BIBFRAME Authority -->
<bf:Person rdf:nodeID=”bnode-x24z100”>
<bf:authorizedAccessPoint>Bartolozzi, Bruno</bf:authorizedAccessPoint>
<bf:hasAuthority rdf:resource=”http://id.loc.gov/authorities/names/n80103954”/>
</bf:Person>Figure 1: BIBFRAME Work with link to creator expressed as BIBFRAME Authority.
The BIBFRAME Authority in this case is of class bf:Person, which is a subclass of bf:Authority, It includes an “authorizedAccessPoint” (which we refer to as an AAP) and a link to an external (actual) authority. The AAP is supplied for the benefit of the user who is unable to follow the link to the external authority, or who is happy to get just the AAP. The external link is supplied for the benefit of the user who wants more than just the AAP and who is able to follow the link.
In the above example the BIBFRAME Authority is a blank node. Figure 1A is the same as figure 1 except that the BIBFRAME Authority takes the form of a re-usable resource. It is an implementation decision whether to represent a BIBFRAME Authority as a blank node or re-usable resource. All remaining examples (beyond Figure 1A) use blank nodes.
<bf:Work>
<bf:title>Collage</bf:title>
<bf:creator rdf:resource=”http://www.example.bibframe.org/authority/bartolozzi/”/>
</bf:Work>
<!-- BIBFRAME Authority -->
<bf:Person rdf:about=”http://www.example.bibframe.org/authority/bartolozzi/”>
<bf:authorizedAccessPoint>Bartolozzi, Bruno</bf:authorizedAccessPoint>
<bf:hasAuthority rdf:resource=”http://id.loc.gov/authorities/names/n80103954”/>
</bf:Person>
Figure 1A: Same example as previous except BIBFRAME Authority is a re-usable resource rather than blank node.
The external authority in this example is a NAF authority; however any legitimate authority may be used instead, for example VIAF.
In fact, multiple links to external authorities are permitted, as shown in the following example. Multiple external authorities might be supplied to increase the likelihood that a user will be able to follow at least one. In the example, both a NAF and VIAF authority are supplied, by properties bf:hasAuthority and bf:referenceAuthority respectively. We refer to these informally as a “primary authority” and a “reference authority”
The presence of a primary authority indicates that the AAP, if supplied, is derived from that authority. For a reference authority, no such guarantee is implied (a reference authority might have a different heading than the primary authority). A BIBFRAME Authority should have at most one primary authority and may include any number of reference authorities.
<!— BIBFRAME Authority -->
<bf:Person>
<bf:authorizedAccessPoint>Cutright, Paul Russell, 1897-</bf:authorizedAccessPoint>
<bf:hasAuthority rdf:resource=http://id.loc.gov/authorities/names/n80022903”/>
<bf:referenceAuthority rdf:resource=”http://viaf.org/viaf/91312848/”/>
</bf:Person>
Figure 2: Multiple Links to external authorities.
A BIBFRAME Authority need not include any links at all. Instead, it might supply authority information inline:
<!— BIBFRAME Authority -->
<bf:Person>
<bf:authorizedAccessPoint>Cutright, Paul Russell, 1897-</bf:authorizedAccessPoint>
<bf:hasAuthority>
<!-- -->
<madsrdf:PersonalName>
<madsrdf:authoritativeLabel>Cutright, Paul Russell, 1897-</madsrdf:authoritativeLabel>
<madsrdf:elementList rdf:parseType="Collection">
<madsrdf:FullNameElement>
<madsrdf:elementValue>Cutright, Paul Russell,</madsrdf:elementValue>
</madsrdf:FullNameElement>
<madsrdf:DateNameElement>
<madsrdf:elementValue>1897-</madsrdf:elementValue>
</madsrdf:DateNameElement>
</madsrdf:elementList>
</madsrdf:PersonalName>
<!-- -->
</bf:hasAuthority>
</bf:Person>
Figure 3: Authority Information Inline.
In the above example, information is supplied according to a legitimate authority ontology using the namespace for that ontology. In this case it is MADS, but it could be another ontology.
A BIBFRAME Authority need not include an authority (primary or reference):
<!— BIBFRAME Authority -->
<bf:Person>
<bf:authorizedAccessPoint> Cutright, Paul Russell, 1897-</bf:authorizedAccessPoint>
</bf:Person>Figure 4: BIBFRAME Authority consisting of AAP alone.
In Figure 4, an AAP is provided, as a hint that this is what the authorized heading would be if there were an authority given. If the supplier of the BIBFRAME Authority is not confident of that, a bf:label may be supplied instead, as shown in the next example. We refer to a bf:label informally as a “label”:
<!— BIBFRAME Authority -->
<bf:Person>
<bf:label>Paul Russell Cutright</bf:label>
</bf:Person>
Figure 5: BIBFRAME Authority consisting of label alone.
3. BIBFRAME Authority Specification
A BIBFRAME Authority is an RDF structure of class bf:Authority (or a subclass of bf:Authority, e.g. bf:Person, etc.) which includes:
- An AAP or Label. It should include one or the other, and may include both, but not more than one of either. If both are supplied, their values should be identical. If a primary authority is supplied, then an AAP should be supplied.
- A primary authority. (Via property bf:hasAuthority.) Optional, non-repeatable.
- A reference authority. (Via property bf:referenceAuthority.) Optional, repeatable
Note: the “Direct Approach” (suggested in an earlier BIBFRAME paper, and illustrated in the following example) is expressly excluded as a possible form for a BIBFRAME Authority.
<bf:Work>
<bf:title>Florida Mobile Home Act</bf:title>
<bf:creator rdf:resource="http://id.loc.gov/authorities/names/n79053995"/>
</bf:Work>Figure 6: “Direct Approach” – NOT a valid form of BIBFRAME Authority.
4. Representing Roles
The BIBFRAME class bf:Authority has subclasses bf:Agent, bf:Place, bf:Temporal, and bf:Topic. Thus an Authority can express an agent, place, temporal expression, or topic.
bf:Agent has subclasses bf:Person, bf:Family, bf:Organization, bf:Jurisdiction and bf:Meeting, thus an agent is a person, family, organization, jurisdiction, or meeting. An agent may be associated with a BIBFRAME Resource via a role, such as “creator” or “illustrator”. This section focuses on agents and their roles.
A role is best expressed as a property (e.g. bf:creator) if there is a known property for the role. In cases where there is no known property to express a role, it may be expressed via string, using a bf:Relator construct. These two mechanisms are described in the following two subsections.
4.1 Role Expressed as Property
Consider for example the aforementioned two roles, creator and illustrator. There is a fairly significant difference in the way that they are treated in BIBFRAME: There is a property bf:creator, but no property bf:illustrator. So, to indicate that a person is a creator is far simpler than to indicate that that person assumes a more specific role such as illustrator.
The role of creator is illustrated in Figure 1, where a BIBFRAME Work includes the property bf:creator, whose object is a BIBFRAME Authority.
There are two such general role properties in BIBFRAME, bf:contributor and bf:creator. The number of more specific potential roles is essentially unlimited, and these cannot possibly be represented by BIBFRAME properties; instead, many are represented by controlled codes or terms within external vocabularies, which we refer to as “role vocabularies.” An example is http://id.loc.gov/vocabulary/relators. Entries within a role vocabulary can be treated as properties.
In the following example the role of illustrator is expressed by the property relators:ill whose object is a BIBFRAME Authority (bf:Person). The prefix ‘relators:’ represents the namespace URI http://id.loc.gov/vocabulary/relators, and so relators:ill becomes http://id.loc.gov/vocabulary/relators/ill which is the id.loc.gov relator code for the term ‘Illustrator’.
<bf:Work xmlns:relators="http://id.loc.gov/vocabulary/relators">
<bf:title>Mogie: the heart of the house</bf:title>
<relators:ill rdf:nodeID=”bnode-x31p54”/>
</bf:Work>
<!-- BIBFRAME Authority-->
<bf:Person rdf:nodeID=”bnode-x31p54”>
<bf:authorizedAccessPoint>Rosenthall, Marc, 1949-</bf:authorizedAccessPoint>
<bf:hasAuthority rdf:resource="http://id.loc.gov/authorities/names/n92008281"/>
</bf:Person>
Figure 7: Role Expressed by a Vocabulary Code.
4.2 Role Expressed as String
Suppose a cataloger creating a Work description wants to indicate the role "original author". If there is a vocabulary with a term representing this role, the cataloger is not aware of it.
In this scenario the property bf:relator is used. Its object is a BIBFRAME Relator - a structure of class bf:Relator - which relates an authority with a role. It has property bf:relatorRole, which expresses the role as a literal, and also uses the property bf:agent to link to the BIBFRAME authority that the role applies to. This is illustrated in the following example.
<bf:Work xmlns:relators="http://id.loc.gov/vocabulary/relators"> <rdf:type rdf:resource="http://bibframe.org/vocab/MovingImage"/> <bf:title>Inkheart</bf:title> <bf:relator rdf:nodeID=”bnode-q90w87”/>
</bf:Work>
<!—
BIBFRAME Relator-->
<bf:Relator rdf:nodeID=”bnode-q90w87”>
<bf:relatorRole>original author</bf:relatorRole>
<bf:agent rdf:nodeID="bnode-y65v32"/>
</bf:Relator> <!—
BIBFRAME Authority-->
<bf:Person rdf:nodeID=”bnode-y65v32”> <bf:authorizedAccessPoint>Funke, Cornelia Caroline</bf:authorizedAccessPoint> <bf:hasAuthority rdf:resource="http://id.loc.gov/authorities/names/nr99039757"/> </bf:Person>
Figure 8: Role Expressed by a literal, using a BIBFRAME Relator.
5. Subjects
BIBFRAME subjects are expressed by property bf:subject which has as its object either a BIBFRAME Authority or Work. Thus the object is one of: bf:Agent:, bf:Place, bf:Temporal, bf:Topic, and bf:Work. All of these classes are subclasses of bf:Authority with the exception of bf:Work, which is included so that a Work may have as its subject another Work.
In the following example a Work has a title and a subject, in this case a Topic. The Topic is an Authority.
<bf:Work rdf:about=”http://bibframe/work/w72x43”>
<bf:title>History of the Peloponnesian War</bf:title>
<bf:subject rdf:nodeID=”bnode-t24x38”/>
</bf:Work>
<!-- BIBFRAME Authority-->
<bf:Topic rdf:nodeID=”bnode-t24x38”>
<bf:label>Greece--History--Peloponnesian War, 431-404 B.C.</bf:label>
</bf:Topic>
Figure 9: Subject Authority (Topic).
In the following example, the Work is an analysis of the above Work (Figure 9) and includes that Work as a subject.
<bf:Work>
<bf:title>Analysis of Thucydides History of the Peloponnesian War</bf:title>
<bf:subject rdf:resource=”http://bibframe/work/w72x43”/>
</bf:Work>
Figure 10: Work has a subject which is another Work.
In the following example, the Work has a subject, which is a place, represented by a Place Authority.
<bf:Work>
<bf:title>Gunmen of Winslow</bf:title>
<bf:subject rdf:resource="bnode-p622k123"/>
</bf:Work>
<!-- BIBFRAME Authority-->
<bf:Place rdf:nodeID="bnode-p622k123">
<bf:authorizedAccessPoint>Winslow (Ark.)</bf: authorizedAccessPoint>
<bf:hasAuthority rdf:resource="http://id.loc.gov/authorities/names/n88198885"/>
</bf:Place>
Figure 11: Subject Authority – Place.