The purpose of the Microform chapter of the Lifecycle Data Requirements Guide is to offer a framework that explains the elements (fields) used to capture descriptive data about microform products at the National Archives and Records Administration. This chapter of the guide does not cover data requirements for the entire database of microform products; it contains data requirements for the descriptive data elements only. The framework applies to all descriptions of microform products that NARA makes available to view, rent or purchase - in the regions, in Washington, DC, and in the Presidential libraries. The framework will help us create complete and consistent descriptions by providing guidelines for the content of an element and noting when an authority source is used for the value of an element.
The elements used to describe microform products are divided into three categories:
- the product elements
- the physical occurrence elements
- the roll/fiche elements
The product elements describe the content and features of the microform product, including the title, abstract, dates, access points such as geography, subject, organization or person, and media.
Physical Occurrence Elements
The physical occurrence elements describe the characteristics for each physical occurrence or copy of the microform product, including the viewing location information.
Within each microform product, the characteristics of the individual rolls/fiche associated with that product are also described. The roll/fiche characteristics include the number and title.
The framework for each element consists of:
- a table of characteristics
- definition, purpose, relationship, and guidance statements
- examples, when appropriate
The table of characteristics contains information about the data structure of the element and the rules that affect how it can be used. The definition, purpose, relationship, and guidance statements explain what the element is, what it does, how it relates to other elements, and how to use it. References to elements are in bold. Examples are shown in gray-shaded boxes and are included to illustrate how information should be entered.
The characteristics of each element are:
- whether or not the element is mandatory
- whether or not the element is repeatable
- the data type and length for the element
- whether or not an authority source is used to enter information in the element
- the entity or category in which the element belongs
- whether or not the element can be available to the public
- the label for the element as it appears in Order Online!
What is Mandatory?
Mandatory means information must be entered in the element for a description to be considered complete. The mandatory elements are the minimum description for microform products. Some elements have relationships that require them to be used with other elements; those requirements are described in the relationship statements, not in the mandatory section of the table of characteristics.
What is Repeatable?
Repeatable means information may be entered more than once in one product, physical occurrence, or roll/fiche. For example, because a microform product can have more than one Topical Subject Reference or be available for viewing in more than one location, these are repeatable elements. Because a microform product can have only one Microform Product Number or Title, these are non-repeatable elements.
What is a Data Type?
There are four primary data types:
- variable character length
Variable character length means the information can be any kind of character, number or symbol. Long means the character length can be up to 2 gigabytes. Numeric means the information can only be numbers. Commas cannot be used in numeric elements. The identifier "NW-338-99-005" could not be entered in a numeric data type element because it contains both letters and symbols. Date means the information can only be in a date format (mm/dd/yyyy). Where appropriate, field length limitations are shown in parentheses after the data type.
What is an Authority Source?
In some elements information cannot be entered as free-text, but must be selected from an authority source, such as an authority file, authority list, or thesaurus. Authority sources are used to ensure information is entered into an element consistently to facilitate sorting or searching. Some of the authority sources are created by NARA based on well-known, highly reputable products from the cataloging field, such as the Getty Thesaurus of Geographic Names® (TGN) or the Library of Congress Name Authority File (LCNAF). Some of the authority sources are lists that have been developed by NARA to specifically meet our needs, such as the Specific Access Restriction Authority List or Reference Unit Authority List.
What is Entity Available?
Data describing microform products are arranged in a hierarchy. The highest grouping of data describing microform products is at the product level. The next highest grouping of data describing microform products is at the physical occurrence level. The lowest grouping in the hierarchy is the roll/fiche level.
What is Public Element?
Public Element indicates whether or not the element and its contents can be made available to the general public. A small number of the elements are not appropriate for public display because they are used only for administrative purposes.