LIDO Terminology Resource Representation Type

"The type attribute of the LIDO Resource Representation element qualifies the digital representation of a resource offered by the data provider for online presentation.

It is intended to support online services with respect to the reuse of digital resources that are referenced in the LIDO record. The controlled type vocabulary allows data providers to indicate which variant of a digital resource is described in an instance of the LIDO Resource Representation element. The vocabulary shall support common reuse scenarios such as presenting the digital resource in a search result list, in a detail view, or as downloadable media file. It may also be exploited for retrieval functions such as filtering search results by digital media types.

The top-level terms are defined to distinguish between the best available variant of a digital resource the data provider can offer for online presentation (provided_representation), the variant a data provider has selected for preview purposes (preview_representation), and the image possibly provided as replacement for the digital resource (placeholder). The definitions of the subordinate terms additionally cover the digital media type. It is highly recommended to use one of the more specific terms, provided_3D, provided_audio, provided_image, provided_text or provided_video, to qualify the media type of the best available variant (or variants in case of equivalent quality), and correspondingly, preview_3D, preview_audio, preview_image, preview_text or preview_video, to distinguish the type of the preview variant (or variants in case of equivalent quality).

Note that these terms do not imply any statement about the quality or format of a digital media file. Therefore, it is recommended to describe the media file in more detail by using the respective LIDO elements and attributes defined for the LIDO Resource Set. As a general recommendation, at a minimum the media file format should be specified by the LIDO formatResource attribute.

Do not confuse the IANA Media Types, formerly known as MIME types, as used for the attribute formatResource with the media type defined as an attribute value for the LIDO Resource Representation element. While the former refers to the type and subtype of the actual media file (e.g., audio/mpeg, image/png, or text/html), the latter differentiates the digital resources by their intended use and generic kind of medium (e.g., provided_audio, preview_image, or provided_text).

The use of the LIDO Resource Measurement Set may depend on specific use cases of an online service. It is recommended that partners in a data exchange or aggregation context reach an agreement about this.

The vocabulary for the type attribute of the LIDO Resource Representation element does not provide terms to designate variants of digital resources with respect to data exchange in the long term preservation context. The vocabulary may be extended, if necessary."