Participants in VIA contribute their locally created cataloging in a common metadata format. Because VIA serves as a union catalog for many institutions with different kinds of visual materials and different research perspectives, the data elements in the VIA metadata format are more general than those in the contributors' local data. The OLIVIA support team can help new contributors determine how to map their existing data into the VIA format.
The metadata format defined by the VIA Access Working Group draws upon many nascent standards, particularly the Visual Resources Association Core Categories. XML is used as the transport syntax, and the VIA DTD and associated files are available from the Harvard University Library Office for Information Systems. The relationship of VIA metadata to existing standards is explained in The Development and Context of VIA Metadata Standards.
Record StructureList of ElementsControlled VocabulariesDevelopment and Context of VIA Standards
Each VIA record is a container with a unique record identifier. Each record contains one or more descriptive segments in up to a 3-level hierarchy. Each segment describes a group of works, a single work, or a surrogate (a visual representation of a work or group).
Here are definitions for each type of VIA record segment:
- A work segment describes an original work (e.g., sculpture, building, painting, print, photograph, etc.). A work segment can occur by itself, or it can contain one or more surrogate segments.
- A group segment provides an aggregate description of a group of works, some of which must also be described individually as subworks within this segment. A group may be commercially produced as a set, exist as an intellectual set (e.g., a group made by the artist/photographer/architect), or be deliberately grouped together for other reasons (e.g., a folder of photographs from an archival collection).
If a group segment is present, it must contain one or more subwork segments that describe individual works in the group. Where multiple works are described together, but none are described separately, use the work segment for the aggregate description.
Optionally, a group segment can contain one or more surrogate segments if there is a need to describe visual representations of the group.
- A subwork segment describes an individual work as it appears within a group of works. Subworks are always contained within a group segment and are never used alone. Each subwork segment optionally can contain one or more surrogate segments.
- A surrogate segment describes a visual representation of a work, group, or subwork. For example, a work describes the “original” item being cataloged while the surrogate describes the representation (i.e., the slide or photograph depicting the work). A surrogate segment is always contained within a work, group, or subwork segment and is never used alone.
In a single VIA catalog record, there may be zero or one group segments. Or, if the record contains no group segment, it must contain exactly one work segment. The following diagram illustrates the record segment combinations that are possible in a VIA record: