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Type Element Working Draft, 1998-09-18


Type Element Working Draft

Date Issued:
Is Replaced By:
Latest Version:
Status of Document:
This is a DCMI Working Draft
Description of Document: The Dublin Core™ Resource Type (DC.Type) element is used to describe the category or genre of the content of the resource. For the sake of interoperability, the primary value should be selected from the enumerated list presented here.

Resource Type Position Paper (Revised)

The Dublin Core™ Resource Type (DC.Type) element is used to describe the category or genre of the content of the resource. For the sake of interoperability, the primary value should be selected from the enumerated list presented here.

  • text
  • image
  • sound
  • dataset
  • software
  • interactive
  • event
  • physical object

These can be defined and used as follows:

resources in which the content is primarily words for reading. For example - books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre "text".
the content is primarily symbolic visual representation other than text. For example - images and photographs of physical objects, paintings, prints, drawings, other images and graphics, animations and moving pictures, film, diagrams, maps, musical notation. Note that "image" may include both electronic and physical representations.
the content is primarily audio. For example - music, speech, recorded sounds.
structured information encoded in lists, tables, databases, etc., which will normally be in a format available for direct machine processing. For example - spreadsheets, databases, GIS data, midi data. Note that unstructured numbers and words will normally be considered to be type "text".
computer programs in source or compiled form which may be available for installation non-transiently on another machine. For software which exists only to create an interactive environment, use interactive instead.
resources which require interaction from the user to be understood, executed, or experienced. For example - forms on web pages, applets, multimedia learning objects, chat services, virtual reality.
non-persistent, time-based occurence. Metadata for an event provides descriptive information that is the basis for discovery of the purpose, location, duration, responsible agents, and links to related events and resources. Event metadata may not identify a retrievable resource if the described instantiation has expired or is yet to occur. Examples - exhibition, web-cast, conference, workshop, open-day, performance, battle, trial, wedding, tea-party, conflagration.
Additional explanation for users:
The occurrence of an event may involve the transformation of source resources (such as scripts, scores, artefacts, etc) and may lead to the creation of derived resources (such as a film, tape, transcript, image, pile of ash, etc) but the event has a fundamental identity separate from these other resources. Another function of a record for an event is as an anchor to tie back to from related items where there is a large number of them. For example, rather than listing the entire contents of an exhibition in the record for the exhibition, the records for the individual items could point to the exhibition record through Relation=IsPartOf.
physical object
three dimensional objects or substances which are not primarily text or image or one of the other types listed here. For example - a person, a computer, the great pyramid, a sculpture, wheat. Note that digital representations of, or surrogates for, these things should use "image/graphic", "text" or one of the other types.

Notes and future work

The concept of a Compound or Mixed resource type and the concept of a Collection were both under close scrutiny and discussion, but were rejected as values for DC.Type for Simple Dublin Core™. The reasons for not including these in the list of unqualified allowed for DC.Type metadata was due to retrieval considerations.

For Compound Resources, greater precision for searching for would be achieved by using the more specific DC.Type descriptors - if necessary in multiple usage. For example, a multimedia program with a single URL might have repeated DC.Types:

  • DC.Type = sound
  • DC.Type = interactive
  • DC.Type = text
  • DC.Type = image

In general metadata providers should use as many DC.Type elements as necessary to indicate the significant content of the resource.

Collection was considered but rejected because another Resource Type would often apply as its primary type. Collection can be brought out in a Relation element. It will also be considered as a subelement or subtype of Resource Type for qualified Dublin Core™ (e.g. Text.Collection).

Further refinement of the vocabulary for DC.Type will build on the above-mentioned list. We expect this to mainly involve sub-typing, for example including terms to indicate such things as moving vs. still images, different types of text, etc.