NSDL Metadata Guidelines

The NSDL has defined a set of tags that extend the Dublin Core metadata schema with information they find pertinent to their collections. Nothing added by NSDL is required. However some elements are recommended.

Element Usage Definition / Notes Tag
Alternative Title Recommended if applicable A refinement of the Title element used to express varying form(s) of a title [e.g., Journal of polymer science (title); Polymer symposia (Alternative Title)]. <dct:alternative>…</dct:alternative>
Education Level Strongly recommended Use to describe the appropriate learning level or range associated with a resource. A refinement of the audience element. NSDL controlled vocabulary available. <dct:educationLevel>…</dct:educationLevel>
Audience Recommended A broad category that best describes the recipient or user for whom the resource is primarily intended. NSDL controlled vocabulary available. <dct:audience>…</dct:audience>
Mediator Optional A class of entity that mediates access to the resource and for whom the resource is intended or useful. <dct:mediator>…</dct:mediator>
Access Rights Optional Information describing conditions or requirements for viewing and/or downloading NSDL material. NSDL controlled vocabulary available; a refinement of the Rights element. <dct:accessRights>…<dct:accessRights>
License Optional A legal document giving official permission to do something with the resource. A refinement of the Rights element. <dct:license>…</dct:license>
Spatial Optional Spatial characteristics of the intellectual content of the resource. <dct:spatial>…</dct:spatial>
Temporal Optional Temporal characteristics of the intellectual content of the resource. <dct:temporal>…</dct:temporal>
Created Recommended A refinement of the Date element <dct:created>…</dct:created>
Available Optional A refinement of the Date element <dct:available>…</dct:available>
dateAccepted Optional A refinement of the Date element <dct:dateAccepted>…</dct:dateAccepted>
dateCopyrighted Optional A refinement of the Date element <dct:dateCopyrighted>…</dct:dateCopyrighted>
dateSubmitted Optional A refinement of the Date element <dct:dateSubmitted>…</dct:dateSubmitted>
Issued Optional A refinement of the Date element <dct:issued>…</dct:issued>
Modified Optional A refinement of the Date element <dct:modified>…</dct:modified>
Valid Optional A refinement of the Date element <dct:valid>…</dct:valid>
Interactivity Type Recommended if applicable The type of interactions supported by a resource (active, expositive, mixed, undefined) <ieee:interactivityType>…</ieee:interactivityType>
Interactivity Level Recommended if applicable The level of interaction between a resource and end user; that is the degree to which the learner can influence the behavior of the resource (very high, high, medium, low, very low) <ieee:interactivityLevel>…</ieee:interactivityLevel>
Typical Learning Time Optional The typical amount of time for a particular education level to interact with the resource. <ieee:typicalLearningTime>…</ieee:typicalLearningTime>
Extent Optional The size or duration of the resource. <dct:extent>…</dct:extent>
Medium Optional The material or physical carrier of the resource. <dct:medium>…</dct:medium>
Relation Recommended if applicable A related resource. Best practice to express relationships to related resources and the item being cataloged is to employ the applicable refinements below. Enter either the title and/or URL of the related resource. <dc:relation>…</dc:relation>
  • conformsTo
A refinement of the Relation element. Also used to provide educational
standard via a URI (e.g. as ASN URIs).
<dct:conformsTo>…</dct:conformsTo>

<dct:conformsTo
xsi:type=”dct:URI”>http://purl.org/ASN/resources/S1014D95</dct:conformsTo>

  • isFormatOf
A refinement of the Relation element <dct:isFormatOf>…</dct:isFormatOf>
  • hasFormat
A refinement of the Relation element <dct:hasFormat>…</dct:hasFormat>
  • isPartOf
A refinement of the Relation element <dct:isPartOf>…</dct:isPartOf>
  • hasPart
A refinement of the Relation element <dct:hasPart>…</dct:hasPart>
  • isReferencedBy
A refinement of the Relation element <dct:isReferencedBy>…</dct:isReferencedBy>
  • references
A refinement of the Relation element <dct:References>…</dct:References>
  • isReplacedBy
A refinement of the Relation element <dct:isReplacedBy>…</dct:isReplacedBy>
  • replaces
A refinement of the Relation element <dct:replaces>…</dct:replaces>
  • isRequiredBy
A refinement of the Relation element <dct:isRequiredBy>…</dct:isRequiredBy>
  • requires
A refinement of the Relation element <dct:requires>…</dct:requires>
  • isVersionOf
A refinement of the Relation element <dct:isVersionOf>…</dct:isVersionOf>
  • hasVersion
A refinement of the Relation element <dct:hasVersion>…</dct:hasVersion>
Abstract Optional A summary of the content of the resource. A refinement of the Description element <dct:abstract>…</dct:abstract>
Table of Contents Optional A list of subunits of the content of the resource. A refinement of the Description element <dct:tableOfContents>…</dct:tableOfContents>
Bibliographic citation Optional A bibliographic reference for the resource. A refinement of the Identifier element <dct:bibliographicCitation>…</dct:bibliographicCitation>
Instructional method Optional Describes process by which knowledge, attitudes, and/or skills are instilled. <dct:instructionalMethod>…</dct:instructionalMethod>
Provenance Optional Statement of ownership and custody of the resource since its creation that are significant for its authenticity, integrity, and interpretation. <dct:provenance>…</dct:provenance>
Accrual method Optional Method by which items are added to a collection; rarely used in NSDL. <dct:accrualMethod>…</dct:accrualMethod>
Accrual periodicity Optional Frequency with which items are added to a collection; rarely used in NSDL. <dct:accrualPeriodicity>…</dct:accrualPeriodicity>
Accrual policy Optional Policy governing the addition of items to a collection. <dct:accrualPolicy>…</dct:accrualPolicy>

Additionally information on the NSDL format, including their interpretations of DC can be found at the NSDL_DC Metadata Guidelines page.