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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.
- 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
- 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
- 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,
- 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.