Media Exchange Metadata User Guide

In order to provide descriptions of media items for the Media Exchange, a metadata scheme, based on the Public Broadcasting Metadata Dictionary, called PBCore, is in use. Each data field in the Media Exchange is defined in this Metadata Guide. There are good ways and there are improper ways to enter descriptions.  This guide supplies the usage guidelines you should follow. Use an entry in the alphabetical listing below.


Down the pageAlphabetical Index to Media Exchange Descriptors
Down the pageWhat is Metadata, Anyway?

 

ALPHABETICAL INDEX TO MEDIA EXCHANGE DESCRIPTORS

elementAcademic disciplines-general elementContact web site elementKeywords--temporal coverage elementSound sampling rate
elementAcademic disciplines-specific elementContent flags elementKeywords--topics represented elementSource of format ID/file name
elementAlternative modes elementCopyright date elementMedia type elementSubmission ID
elementAnnotation elementCopyright holder elementPhysical format elementSubmission ID source
elementAudience levels elementCopyright status elementPrimary language(s) elementThis title is a(n)
elementAudience ratings elementDescription narrative elementRelated item (parent) elementTitle
elementAuthor-creator (others) elementDigital format (MIME type) elementRelated items (children) elementTotal data rate
elementAuthor-creator (primary) elementDigital or physical types elementRelated items (siblings) elementVisual aspect ratio
elementAvailability end date elementDuration of media item elementRights-Under these constraints elementVisual bit depth
elementAvailability start date elementFile size elementRights-With these obligations elementVisual colors
elementComes from a collection named elementFormat's unique ID/file name elementRights-You are permitted to elementVisual data rate
elementContact address elementFunding credit elementSimilar media items elementVisual encoding
elementContact e-mail elementGenre authority used elementSound bit depth elementVisual frame rate
elementContact name elementGenres elementSound data rate elementVisual frame size
elementContact organization elementKeyword authority used elementSound encoding elementVisual media standard
elementContact phone elementKeywords--spatial coverage elementSound media standard  

 

 

WHAT IS METADATA, ANYWAY?

“Metadata” is descriptive information about a resource. The resource may be video or audio, an image or graphic, a text-based document, or any other informational item whether electronic or not.

The primary purpose of metadata is to enhance findability and facilitate sharing...the ability to describe a resource and allow someone to discover, review, select, and retrieve an item.

Examples of metadata include the name of an item; descriptions or abstracts about its content; keywords or subject classifications; file formats; authors; producers; distributors; publishers; copyright and usage restrictions; etc.

Metadata needs to be structured in some way. The descriptions available through metadata should not be created in a random or ad hoc manner. In other words, metadata should follow a well-documented, formalized scheme. The flip side of using standardized metadata schemes is called "Folksonomy" and is described in a Wikipedia article ...

In contrast to professionally developed taxonomies with controlled vocabularies, folksonomies are unsystematic and, from an information scientist's point of view, unsophisticated; however, for Internet users, they dramatically lower content categorization costs because there is no complicated, hierarchically organized nomenclature to learn. One simply creates and applies tags on the fly.

The Media Exchange project has chosen the Public Broadcasting Metadata Dictionary, PBCore, as its metadata system for describing media items. It is well researched and well documented (see http://www.pbcore.org). PBCore provides a consistent foundation upon which descriptions can be created and entered into cataloging systems, thus avoiding the ad hoc nature of folksonomies.

We have also extended the PBCore to provide some additional metadata fields that to meet the requirements of the Media Exchange project. This Metadata User Guide documents both the PBCore descriptors and our unique additions.

By the way, the "descriptions" are called "metadata." However, the "thing" being described is often referred to as the "essence." Essence + Metadata yields a media asset that has value to various end-user communities.

An online Metadata Primer is also available from the NSDL--the National Science Digital Library.