AN INTRODUCTION TO METADATA
Defining Elements: Attributes

The actual name of the descriptor or element.

A metadata element does NOT necessarily have to be used or contain description data when cataloging a media item. The "Obligation to Use" a metadata element is defined by these three options in the PBS DLL...

• MANDATORY:
  This small group of elements is required in order to provide basic descriptions about a media item and to facilitate searching.
• OPTIONAL:
  This set of metadata elements can be supplied by contributors if the descriptions exist and will enhance the findability of media items from the repository.
• PROVIDED BY PBS:
  This set of metadata is primarily supplied by PBS itself for each contributed media item and includes the correlations of media items to state and national core curriculum educational subject areas and learning objectives.

A brief definition of the descriptor or element. Guidelines for understanding how to use an individual metadata element in the PBS DLL are described under the attribute "Notes/Guidelines."

Although not officially part of the ISO/IEC 11179 specification, PBS DLL documents each element by referencing how it is paired or bound to other elements in the Dictionary. Often, entering a value for one metadata element pre-determines the availability of or the options you can choose in other related elements. One element depends on another.

In order to better control the terms and descriptions used while cataloging, some metadata elements prescribe ways to refine or enter your data, using formal notations, vocabularies or parsing rules.

• Use a short listing of prescribed terms, often called a "controlled vocabulary." The best practice is to select a term or terms from a picklist. The picklist insures consistency in data entry.
• Use an "authority file" from another agency that specifies how to properly enter descriptive information or choose from large numbers of values for a metadata element. It may provide taxonomies of terms organized into logical hierarchies, such as the state and national educational core curriculum subject headings and learning objectives.
• Follow a particular syntax, punctuation or grammar when entering data, e.g., LastName, FirstName MiddleName, Credentials. In the PBS DLL Metadata User Guide, the parsing rules are captured under the attribute "Notes/Guidelines."

Controlling or prescribing consistent descriptions that can be entered for a metadata element ultimately means that end users are able to conduct successful searches for relevant media items.

The PBS DLL Metadata User Guide also indicates in the attribute CONTROLLED VOCABULARY if one is not required to use pre-selected terms, meaning you may enter Free Text for a particular metadata element.

Some metadata schemas allow you to enter more than one descriptive term or phrase for an element, where multiple terms need to be supplied in order to convey sufficient and complete information. For example, the element creatorOther may have two entries, one for "Alan Smithee" and one for "Lucida Grande." This attribute is often defined as REPEATABLE, UNBOUNDED, MINIMUM OCCURENCE or MAXIMUM OCCURENCE.

The PBS DLL Metadata User Guide has simplified the definitions in order to indicate the MINIMUM OCCURRENCE allowed and the MAXIMUM occurrence allowed.

Two numbers or terms are displayed, the first is the Minimum, the second is the Maximum. Here are the permutations you will see...

• 0-1
  (Optional to supply any metadata, but if you do, only 1 occurence is allowed for data entry)
• 0-Unlimited
  (Optional to supply any metdata, but if you do, you can continue to enter an unlimited number of values, terms, or phrases)
• 1-1
  (It is mandatory to enter a description, value or term, and only one occurrence is allowed for data entry)
• 1-Unlimited
  (It is mandatory to enter a description, value or term, and you can continue to enter an unlimited number of values, terms or phrases)

Any database designer must indicate what type of data is permitted for a field. The type of data permitted is often defined as TEXT STRING, NUMBER, INTEGER, DATE, DATETIME, TIME, CHAR, etc. PBS DLL metadata uses relatively few data entry types. Most are Text Strings.

The Guidelines are a brief user's guide to understanding the best practice and procedure in entering data for an element. Clarifications are offered about intended meanings for an element and how terms are defined. References to sites or documents with additional explanations are included, as are examples of metadata entries.

To illustrate the proper formatting and use of an element, the PBS DLL Metadata User Guide supplies many real world examples of data entires for your review.

Also provided are examples of full records of metadata descriptions for Video, Audio, Images, Documents, and Interactives; select the entry in the left-hand Table of Contents called View the Metadata Elements > Samples of Full Metadata Records.

Indicates the current version of the PBS DLL Metadata as documented in the Metadata User Guide and in use in any metadata and media item exchanges between content contributors and the PBS DLL Media Management and Distribution System.