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8. Details of Individual Metadata Elements
8.43 Subject
Attributes
Attribute
Value
Identifying Attributes
Name
subject
Label
Subject
Defined by
Dublin Core Metadata Element Set, v1.1
http://purl.org/dc/elements/1.1/
Element URI
http://purl.org/dc/elements/1.1/subject
Definitional Attributes
DC Definition
The topic of the content of the resource.
DC Comment
Typically, a Subject will be expressed as keywords, key phrases or classification codes that describe a topic of the resource. Recommended best practice is to select a value from a controlled vocabulary or formal classification scheme.
Purpose
To find records on the same subject consistently and efficiently.
Rationale
"A useable record is one that can be located, retrieved, presented and interpreted." ISO International Standard 15489-1, 7.2.5
"The primary purpose of registration is to provide evidence that a record has been created or captured in a records system, and an additional benefit is that it facilitates retrieval. It involves recording brief descriptive information or metadata about the record and assigning the record an identifier, unique within the system." ISO International Standard 15489-1, s. 9.4
"Metadata should be used to identify records and facilitate their retrievability and usability in records systems." ISO Technical Specification 23081-1, s. 9.2.3
"Metadata for accessibility should do the following … e) document descriptive information that facilitates record use and understanding, such as a subject ..." ISO Technical Specification 23081-1, s. 9.2.3.1
"Ongoing description is necessary to keep the records meaningful for use." ISO Technical Specification 23081-1, s. 9.2.3.2
Value Domain
Enumerated strings of text representing subjects.
Datatype Name
String
Constraint
Applicable at record level only.
Obligation
Optional at record level.
Relational Attributes
Encoding Scheme
Terms should be selected from controlled vocabularies registered with Library and Archives Canada (e.g. the Core Subject Thesaurus) or recognized by the Dublin Core Metadata Initiative.
Provided that a term has been selected from a registered controlled vocabulary, additional terms from institution-specific schemes may be selected.
References
http://purl.org/dc/terms/DDC
References
http://purl.org/dc/terms/LCC
References
http://purl.org/dc/terms/LCSH
References
http://purl.org/dc/terms/MESH
References
http://purl.org/dc/terms/UDC
Conditions of Application - Record
Format
Text, based on encoding scheme.
Modifiable
Pre Record Declared Locked
Post Record Declared Locked
Yes
No
Occurrence
Repeatable
Conditions of Application - File
Format
-
Modifiable
-
Occurrence
-
Comments and Guidance
a) Explanation of Definition/Usage
This descriptive element relates to the content of the record.
This element is not to be confused with the element Description which gives a narrative of the record, or with elements File Name and File Code which serve to link the record to a classification scheme / file plan for life cycle management. Also, Subject does not describe the Type (i.e. the genre) of the record.
b) Best Practices
TBITS 39.2 (www.tbs-sct.gc.ca/its-nit/standards/
tbits39/crit392_e.asp ) specifies that a registered controlled vocabulary must be used for the Subject element. This must be either the Government of Canada Core Subject Thesaurus (CST) or another thesaurus that has been registered by the Library and Archives Canada thesaurus registry service (www.collectionscanada.gc.ca/government/controlled-vocabularies/index-e.html) or registered by the Dublin Core Metadata Initiative (http://dublincore.org/dcregistry/navigateServlet). One or more terms from one of these registered vocabularies must be entered as a value for the Subject element.
Once at least one term from one of the registered vocabularies has been used, users can add subject terms from other institution-based controlled vocabularies (e.g., internal, unregistered), if they wish. Such institution-based controlled vocabularies allow for the identification of specialized terminology used in specific and limited disciplines.
Using terms from a controlled vocabulary to describe the subject of records facilitates access to records produced or collected by many different creators. Using standardized terminology from one or more lists of controlled subject terms or thesauri allows searchers to find records on the same subject consistently and efficiently.
Subject terms should be as specific as possible, not too broad or too narrow. Use of a broad term such as "Dairy industry" to describe a record on a specific topic such as "milk" would mean that users searching for records on "milk" would not find the record. Similarly, terms for individual dairy products should not be used for a record focusing on the dairy industry as a whole, even if particular products are mentioned in the record.
Users should apply as many terms as are required to describe the record accurately.
Further guidance on controlled vocabularies may be found in the following document: Controlled Vocabularies Sub-Group, Government On-Line Metadata Working Group, Guide to the Development and Maintenance of Controlled Vocabularies in the Government of Canada, July 8, 2005. [url forthcoming].
Once a record is locked, the value for this element may not be modified.
c) Obligation
This element is deemed optional because it is descriptive only and is not necessary for the management of the record or file through the information management life cycle.
d) Default Values/Auto-populate
If a user works primarily with records in a particular subject area, a default value may be applied but this situation will occur rarely.
e) Linkages
None.
f) Examples
- "Records Management; Metadata"
- "Environment agreements; Environmental policy"
