# Presentation: 618124

## METS in the OCLC Digital Archive 

**Taylor Surface**
**Director, Digital Content Management Services**
**October 27, 2003**

## Agenda

- OCLC’s Digital Archive
- Our METS implementation
- Extension schemas
- Description, vocabularies, requirements

**Notes:**
OCLC uses METS in accordance with the last two initials of the name ... “Metadata Encoding Transmission Standard”. In other words, as an operational digital repository, the OCLC Digital Archive needs to have the ability to exchange digital objects with other repositories in a standard manner. In order to promote  trust in a digital repository the repository operator needs to re-assure you that if you entrust something to them that you’ll be able to get it back. One element of that trust is built around openly-defined input streams for submission of objects to the repository as well as output streams for dissemination of objects to users or external systems.

## OCLC Digital Archive Tools 

**Web Archiving**
- Item-by-item archiving of web pages and web documents
- HTML and PDF and associated files
- DIP uses METS; SIP is constructed on the fly

**Batch Ingest**
- Collection-based archiving of resources library has saved onto server, disc, or tape
- Primarily TIFFs
- SIP uses METS; DIP not implemented at this time

## Implications for OCLC’s METS Implementation

- Different profiles needed for batch ingest and web tool
- Batch ingest currently accepts nonhierarchical objects only

**Notes:**
So, the two channels of object ingest that we’ve developed lend themselves to different specializations. Serving these communities required us to develop with a different emphasis in each area.

We fully anticipate that there are standard profiles that we’ll be able to utilize or develop with others in the community. Presently we have not published profiles for any formats or for the digital archive service as a service.

As I progress through the remainder of this presentation you’ll get a feel for how the profiles will be developed and what they’ll look like.

## METS in Batch Ingest

- Downloadable Submission Builder application creates SIP
- Submission Builder creates METS document based on user’s tab-delimited metadata file and manifest file (list of filenames)
- Manifest file, also part of SIP, is encoded in METS and has links to object-level METS file

## METS in Batch Ingest (SIP)

- METS document (one per object) sent to OCLC as part of SIP, along with content objects for batch ingest
- Objects are ingested and preservation metadata records are generated automatically based on the information in SIP

## Submission Builder Requirements

- Windows 2000, NT4, or XP
- Intel Pentium III, 864MzH or higher
- At least 256 MB RAM
- 8.5 MB disk space
- Internet connection active during SIP creation (validates against METS at LC web site)

## Submission Builder

## METS in Web Archiving Tools (DIP)

- The dissemination of content objects ingested on an object-by-object basis results in a METS document.
- Hierarchical as well as non-hierarchical objects are encoded in METS for use as a DIP from OCLC Digital Archive.

## Development Plans

- METS-based batch dissemination for both batch ingest and web tools
- Acceptance of hierarchical objects in batch ingest
- Keeping profiles updated as tools change

## METS Extension Schemas

- Header - No extension
- Descriptive Metadata Section - OCLC descriptive schema _[http://](http://digitalarchive.oclc.org/schemas/oclc_dm.xsd)__[digitalarchive](http://digitalarchive.oclc.org/schemas/oclc_dm.xsd)__[.oclc.org/schemas/oclc_dm.](http://digitalarchive.oclc.org/schemas/oclc_dm.xsd)__[xsd](http://digitalarchive.oclc.org/schemas/oclc_dm.xsd)_
- File Section - No extension
- Structural Map Section - No extension
- Behavior Section - No extension

## More Extension Schemas

- Administrative Metadata Section –
- 	MIX schema _[http://www.loc.](http://www.loc.gov/standards/mix/mix.xsd)__[gov](http://www.loc.gov/standards/mix/mix.xsd)__[/standards/mix/mix.](http://www.loc.gov/standards/mix/mix.xsd)__[xsd](http://www.loc.gov/standards/mix/mix.xsd)_
- 	textMD schema _[http://](http://dlib.nyu.edu/METS/textmd.xsd)__[dlib](http://dlib.nyu.edu/METS/textmd.xsd)__[.](http://dlib.nyu.edu/METS/textmd.xsd)__[nyu](http://dlib.nyu.edu/METS/textmd.xsd)__[.](http://dlib.nyu.edu/METS/textmd.xsd)__[edu](http://dlib.nyu.edu/METS/textmd.xsd)__[/METS/](http://dlib.nyu.edu/METS/textmd.xsd)__[textmd](http://dlib.nyu.edu/METS/textmd.xsd)__[.](http://dlib.nyu.edu/METS/textmd.xsd)__[xsd](http://dlib.nyu.edu/METS/textmd.xsd)_
- 	OCLC provenance schema _[http://](http://digitalarchive.oclc.org/schemas/oclc_prov.xsd)__[digitalarchive](http://digitalarchive.oclc.org/schemas/oclc_prov.xsd)__[.oclc.org/schemas/oclc_](http://digitalarchive.oclc.org/schemas/oclc_prov.xsd)__[prov](http://digitalarchive.oclc.org/schemas/oclc_prov.xsd)__[.](http://digitalarchive.oclc.org/schemas/oclc_prov.xsd)__[xsd](http://digitalarchive.oclc.org/schemas/oclc_prov.xsd)_

## Rules of Description, Controlled Vocabularies

- Date: Must be in W3C-DTF format
- Language: Must be in ISO 639-2 format

## Some of Our Structural Requirements

- Every METS document must have <metsHdr>
- Descriptive section: METS document for each object contains one <dmdSec>; metadata conforms to oclc_md schema
- Administrative section: MIX used for image technical metadata; textMD used for text; section also contains provenance information using oclc_prov.xsd OCLC extension schema

## Technical Requirements

- Any version of these formats:
- HTML (including .css and .js)
- PDF
- TXT
- TIF
- JPG
- GIF
- BMP

## Resources

- Digital Archive web site: _[http://www.oclc.org/digitalarchive/default.](http://www.oclc.org/digitalarchive/default.htm)__[htm](http://www.oclc.org/digitalarchive/default.htm)_
- Navigate to ***Support***,
- then ***Documentation***
- for “Batch Ingest Guide,” and “Learning to Use Web Archiving Tools”: each is a comprehensive guide to that part of the system

## Questions?