AppropriateMetadata
From oaibp
Main Page >> Shareable Metadata
Note: Additional information on the inclusion of technical metadata in records added as per a reviewer comment. Jenn Riley 10/8/05
Note: Summary of best practices added. Jenn Riley 10/11/05
Contents |
[edit] Appropriate Representation of Resources
[edit] Summary of Best Practices
- Think about uses of your metadata in a federated environment, and tailor your OAI records for those purposes.
- Use metadata formats appropriate to your resources and your intended communities.
- Use metadata elements and construct values for those elements appropriate for a shared environment.
- Include the appropriate context for the resource in an OAI metadata record.
[edit] OAI metadata as one *view* of metadata for a resource
It is important to conceive of OAI metadata as one view of metadata for a resource. Good shareable metadata may not be appropriate for use in a local environment. OAI implementers may have local 'master' metadata records from which they create versions of that metadata for specific purposes, including OAI. When creating OAI records, institutions must do their best to envision the uses of this metadata, and support these uses in their OAI records. As of 2005 the vast majority of OAI service providers focus on resource discovery, therefore data providers frequently tailor records meant for OAI exposure for this purpose. Views of metadata for OAI exposure must also take care to include the right amount of information. If too little information is included, records are not discoverable in a shared environment. If too much information is included, users of the shared metadata must wade through extra information in order to target items that interest them. However, when in doubt, err on the side of including too much information.
[edit] Appropriate Metadata Formats
Metadata formats (sometimes called metadata schemas or elements sets) are groups of defined elements, or fields that allow you to say something ' descriptive, technical, administrative ' about a resource. Within the OAI context, most exposed metadata is descriptive metadata, that is, a set of elements that allows you to describe the resource for the purposes of resource discovery or other services that rely on knowing what the resource is or is about.
Many communities have well established metadata formats that are maintained as standards. Use of standard metadata formats is a best practice for shareable metadata. For more information on metadata formats, see the section MultipleMetadataFormats and the section on RecommendedFormats potential metadata formats].
Metadata formats should be appropriate to both the resources described as well as to the communities expected to use the resource. As an extreme example, the Metadata Object Description Schema (MODS) format is not a good format to describe the hierarchy of an archival finding aid; the Encoded Archival Description (EAD) is a much better format for this task. On the flip side, one would not use EAD to describe a single photograph; MODS might be a better choice for this type of resource.
[edit] Appropriate Metadata Content
The information you enter into the fields of a metadata format should describe the resource at an appropriate level, given the content described and the context in which is likely to be used. You should consider element choices and controlled vocabularies that best represent the diversity and range of resources in your collection, not focus on one or two difficult to describe resources.
Many communities maintain controlled vocabularies (such as the Library of Congress Subject Headings) and encoding schemes (such as the W3C encoding scheme for date and time) as standards. Use of appropriate standard controlled vocabularies and encoding schemes, like the use of standard metadata formats, is a best practice for shareable metadata. If it is possible to identify the controlled vocabulary in use [this is not possible in the required oai_dc], it is best practice to do so.
Administrative metadata, used to manage a digital collection and which includes technical and preservation metadata should generally not be exposed in your OAI records. Consider carefully what information is most useful to a service provider or end user. An example of inappropriate exposure of administrative metadata might be multiple date fields describing updates to content or a reference to the type of scanner used to digitize a photograph. If administrative information is included in your metadata, you might consider exposing a 'view' of your metadata (as discussed in the introduction to the Shareable Metadata section) that excludes those fields. The Describing Versions and Reproductions page discusses cases in which it might be appropriate to include some technical metadata.
[edit] Appropriate Context
Problems with insufficient metadata frequently occur because metadata creators see a particular element or piece of information as unnecessary given the larger context of the site or collection; however, when these individual metadata records are disassociated from context (as happens when the records are aggregated), the record becomes confusing or unusable. An example might be where all items in a collection are associated with a particular person, but the metadata records for the individual items do not include the person's name. This is what Robin Wendler has termed the 'on a horse' problem. (See 'The eye of the beholder: challenges of image description and access at Harvard' in Metadata in Practice (Diane I. Hillmann and Elaine Westbrooks, Eds.) For example, if a collection of digitized material is entirely about Mark Twain, the metadata describing this material may not include the subject heading 'Mark Twain' or 'Samuel Clemens', because it is obvious that all resources are about Mark Twain. But when this metadata is made available via OAI, it no longer has its original environment to provide that context. Wendler's descriptive term 'on a horse' comes from a collection about Theodore Roosevelt. Photographs of Roosevelt on a horse simple had the singularly non-useful (out of its local context, at least!) descriptive entry 'On a horse'.
