Type Element Working Draft, 1998-09-18

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:

text

  <dd>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".</dd>

  <dt>image</dt>

  <dd>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.</dd>

  <dt>sound</dt>

  <dd>the content is primarily audio. For example - music,
  speech, recorded sounds.</dd>

  <dt>dataset</dt>

  <dd>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".</dd>

  <dt>software</dt>

  <dd>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.</dd>

  <dt>interactive</dt>

  <dd>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.</dd>

  <dt>event</dt>

  <dd>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.</dd>

  <dd>Additional explanation for users:<br>
   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.</dd>

  <dt>physical object</dt>

  <dd>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.</dd>
</dl>

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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.