Overview

Extent should be recorded at both the collection and file level.

At the collection level, it is recorded using cubic feet for physical materials or in megabytes, gigabytes, or terabytes for digital materials. In addition to calculating the total cubic feet for a collection, a container summary is also recorded to give a breakdown of the numbers and types of containers, or the number of files for digital materials. Container summaries are enclosed in parentheses.

At the file level, it may be described in a more granular fashion, by the number of containers or carriers (e.g., 2 folder(s), 3 cassette(s)). If feasible at this stage, record separate extents for the number and the type of carrier for legacy physical digital and audio-visual material (e.g. things like floppy disks or cassette tapes).

Examples

ExtentContainer Summary
3 cubic feet(3 record cartons)
10.2 cubic feet(10 record cartons, 1 phase box, 1 oversize folder)
83 cubic feet(24 record cartons, 58 manuscript boxes, 1 legal manuscript box)
3 cassettes(2 VHS, 1 Betamax)
2 folders 
91.4 megabytes(79 digital files)
1.5 terabytes(2,429 digital files, 253,374 emails)

Calculating Extent

ContainerDimensionsCubic Feet

Record carton, “Paige” box

15” x 12” x 10”

1
Manuscript box (letter)10.25” x 12.25”x 5”.36
Legal manuscript box10.25” x 15.25” x 5”.45
Half manuscript box (letter)10.25” x 12.25” x 2.5”.18
Legal half manuscript box10.25” x 15.25” x 2.5”.23
Folder or other small items .01

Other containers use this formula:

{\huge \frac{Length \times Width \times Height}{1728} = \text{Extent in Cubic Feet}}

Length x Width x Height (in inches) divided by 1728 = number of cubic feet

Using the Extent Module

Add new extent to a resource record or component by clicking the “Add Extent” button.

FieldHow to Use
PortionRequired. The portion of the extent being recorded —select "Whole" to record an extent of a collection that is entirely analog or digital. For hybrid collections, select "Part" and record the analog and digital extents separately. 
NumberRequired. Numeric field. For analog materials, a numeric value for the number of cubic feet (at collection level) or by container or carrier type (at file or item level). For digital materials, a numeric value for the storage space in megabytes, gigabytes, or terabytes.
TypeRequired. Choose the unit of measurement or carrier type from the drop down menu. See Guide to Extent Types for more information. At the collection level, record extents using cubic feet for physical materials. For digital content choose from megabytes, gigabytes, or terabytes as appropriate.
Container Summary

Required at the collection level. Suggested at file level when additional description is warranted. Free text field. For analog materials, the container summary is used to describe the containers that the materials are housed in, or the carrier format. For digital materials, it is used to describe the size of the digital materials in bytes or digital files. Text in the Container Summary field should be enclosed in parentheses. See Guide to Extent Types for suggested vocabulary.

  • (2 record cartons, 1 legal manuscript box)

  • (5 audiocassettes)

  • (2 VHS, 1 Betamax)
  • (1 folder)

  • (12,345 digital files)

  • (2,429 digital files; 253,374 emails)

  • (3 legal manuscript boxes, 1 manuscript box)

  • (1 archived website)


Physical Details 
DimensionsRequired when indicated in the Guide to Extent Types as necessary for that extent type.

Content Reference

DACS 2.5

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