Announcement: The operation of NSDL has been transferred to ISKME's OER Commons
(effective December, 2014) - Read the news release.
This documentation describes the policies, procedures, and services that existed while NSDL was operated by UCAR.
Note: These NSDL_DC metadata guidelines are were developed in 2007. Though somewhat aged, they are valuable for the detailed and precise nature of the information delivered. Some of the examples provided may refer to resource types or materials that are not currently in NSDL's scope (such as scholarly journals). NSDL's current preferred metadata format for new collection contribution is the LAR metadata format. (Jan. 2013)
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Element | Recommended Usage | Simple definition / Notes | Sample XML tags | |
|---|---|---|---|---|
Title | Required | The name by which the resource or collection of resources is formally known. | <dc:title>...</dc:title> | |
<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="3695f984-4d3c-48d3-84a2-bb5578d22e37"><ac:plain-text-body><![CDATA[ | 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> ]]></ac:plain-text-body></ac:structured-macro> |
Required | URL to the resource | <dc:identifier>...</dc:identifier> | ||
Strongly | Populate each Subject field with only one subject term (or phrase) that describes the topics, concepts or content of the resource; repeat as needed. | <dc:subject>...</dc:subject> | ||
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> | ||
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> | |
Description | Strongly recommended | A free-text account of a resource. May include abstracts or table of contents. Used as primary search field and display field. | <dc:description>...</dc:description> | |
Strongly recommended | The nature, function or typical use of a resource. NSDL controlled vocabulary and DCMI type list available. To describe the file format, physical medium, or dimensions of the resource, use Format element. | <dc:type>...</dc:type> | ||
Recommended | Rights information typically includes a free-text statement about various property rights associated with the resource, including intellectual property rights. May be populated with a URL that links to specific rights language in the resource. | <dc:rights>...<dc: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> | |
Recommended | Entity responsible for making contributions to the resource. Populate each Contributor field with only one contributor term; repeat as needed. | <dc:contributor>...</dc:contributor> | ||
Recommended | Entity primarily responsible for making the resource. | <dc:creator>...</dc:creator> | ||
Recommended | Entity responsible for making the resource available. | <dc:publisher>...</dc:publisher> | ||
Language | Recommended | Primary language of the resource. NSDL_DC recommends use of LOC's ISO 639-2 controlled vocabulary. | <dc:language>...</dc:language> | |
Coverage | Optional | Statement of resource's spatial/geographic and/or temporal coverage. Named places (countries, cities, etc.) or time periods (epochs, date ranges, etc.) are typical Coverage values. | <dc:coverage>...</dc:coverage> | |
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> | |
Date | Recommended | A point or period of time associated with an event in the lifecycle of the resource. Employ W3CDTF encoding scheme that looks like YYYY-MM-DD. | <dc:date>...</dc:date> | |
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> | |
Optional | Physical medium and/or file/MIME format | <dc:format>...</dc:format> | ||
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> | |
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| A refinement of the Relation element. Also used to provide educational standard via a URI (e.g. as ASN URIs). | <dct:conformsTo>...</dct:conformsTo> | |
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| A refinement of the Relation element | <dct:isFormatOf>...</dct:isFormatOf> | |
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| A refinement of the Relation element | <dct:hasFormat>...</dct:hasFormat> | |
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| A refinement of the Relation element | <dct:isPartOf>...</dct:isPartOf> | |
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| A refinement of the Relation element | <dct:hasPart>...</dct:hasPart> | |
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| A refinement of the Relation element | <dct:isReferencedBy>...</dct:isReferencedBy> | |
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| A refinement of the Relation element | <dct:References>...</dct:References> | |
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| A refinement of the Relation element | <dct:isReplacedBy>...</dct:isReplacedBy> | |
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| A refinement of the Relation element | <dct:replaces>...</dct:replaces> | |
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| A refinement of the Relation element | <dct:isRequiredBy>...</dct:isRequiredBy> | |
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| A refinement of the Relation element | <dct:requires>...</dct:requires> | |
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| A refinement of the Relation element | <dct:isVersionOf>...</dct:isVersionOf> | |
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| 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> |
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OAI-PMH requires that all metadata served must be valid according to an XML schema. In other words, every metadata record must be schema valid, and you must indicate the URL of the XML schema, both in ListMetadataFormats responses and in the served records. Note that there is also an XML schema provided for all OAI-PMH responses -- so the OAI wrapper around the served metadata must also be schema valid.Schema validation tools are available to help you with this.
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