This document discusses considerations for migrating content from Fedora 3 to Fedora 4. It describes the key components of Fedora 3 including objects, datastreams, and relationships defined in RELS-EXT. It then examines options for mapping structural metadata like METS and relationships between objects. For descriptive metadata, it outlines three options: 1) using migration tools, 2) mapping to simple RDF statements, or 3) mapping complex metadata to an external triplestore. The document analyzes the tradeoffs of each approach and emphasizes planning based on current metadata and management needs.

1. Fedora migration considerations
Juliet L. Hardesty
Metadata Analyst, Indiana University
Open Repositories, June 15, 2016

2. Fedora 3 diagram key
Repository object
Structural metadata datastream
Descriptive metadata datastream
Other metadata datastream

3. Indiana University President's Office records, 1937-1962.
Subject files, 1937-1962. Aeons, Board of, 1939-1940.

4. Fedora 3 - documents
VAA8877-06169 Fedora
DC
RELS-
EXT
METS
VAA8877-U-03624
Fedora
DC
RELS-
EXT
PDF
VAA8877-U-03624-001
Fedora
DC
RELS-
EXT
MASTER
Derivatives
MASTER-
MIX
Folder
Document in
folder
Page in document
isMemberOfCollection
isPartOf
isPartOf

5. Portable soft drink stand at Bowling Green

6. Fedora 3 - images
P02668 Fedora
DC
RELS-
EXT
METS
PURL
Redirect
isMemberOfCollection
DCMODS
Image

7. [Program, 2013-2014, no. 117]

8. Fedora 3 – time-based media
avalon:22187
Fedora
DC
RELS-
EXT
MODSRIGHTS
SECTIONS
TECH/DIS
PLAY
WORKFLOW
Fedora
DC
RELS-
EXT
STRUCTURE MATTERHORN
avalon:22191
Fedora
DC
RELS-
EXT
STRUCTURE MATTERHORN
Item
CD 1 CD 2
avalon:22189
isMemberOfCollection
TECH/DIS
PLAY
TECH/DIS
PLAY
isPartOf
isPartOf

9. Focusing on Fedora 3 structure
• RELS-EXT defines structure going up
• METS or special datastreams required to
define structure going down
• All in XML as datastreams on objects that
connect together down to the digital file

10. https://github.com/duraspace/pcdm/wiki
Portland
Common
Data
Model

11. Document example in PCDM
Wilcox, David and Andrew Woods. “Hands-On: Seeing Fedora 4 Firsthand.” Fedora 4 Training
Workshop. Open Repositories 2015.

12. METS: fileSec

13. METS: structMap

15. VAA8877-06169 VAA8877-U-03626 VAA8877-U-03626-page1
filesdocuments pages
VAA8877-U-03626Proxy VAA8877-U-03626-page1Proxy
thumb.jpg
screen.jpg
large.jpg
pcdm:
hasMember
pcdm:
hasMember
Fedora 4 structure diagram

16. http://localhost:8080/fcrepo/rest/VAA8877-U-
03625/pages/VAA8877-U-03625-page1Proxy

17. METS as PCDM in Fedora – SPARQL
query
select DISTINCT ?document ?firstPage ?nextPage where {
{ <http://localhost:8080/fcrepo/rest/VAA8877-06169> pcdm:hasMember ?document .
?document iana:first ?firstPageProxy .
?firstPageProxy ore:proxyFor ?firstPage .
}
union
{
<http://localhost:8080/fcrepo/rest/VAA8877-06169> pcdm:hasMember+ ?page .
?page pcdm:hasFile ?f .
?f ebucore:hasMimeType "image/jpeg"^^xsd:string .
?pageProxy ore:proxyFor ?page .
?pageProxy iana:next ?nextPageProxy .
?nextPageProxy ore:proxyFor ?nextPage .
}
}

18. SPARQL query results for structure of
folder VAA8877-06169

19. Transforming METS to PCDM
• Consider structure for collections using METS
• fileSec and structMap
– @GROUPID, @ID, @FILEID (unique identifiers
from both sections) in combination with <div>
structure within structMap can point to grouping
and ordering structure for objects
• Migrating easier if identifiers brought over

20. Considerations for structural metadata
• RELS-EXT in Fedora 3 migrated to Fedora 4
• Other structure datastreams are on you to
map
• METS – possible to map programmatically but
maybe not in a standard way

21. Descriptive Metadata - IU
MODS

22. Fedora 4 options for descriptive
metadata: Option 1
• Migration tools
– migration-utils
– fedora-migrate gem
Neither really takes advantage of Fedora 4/external triplestore
unless original is already RDF; fedora-migrate requires Hydra
Available now, keeps all metadata, nothing lost; can have RDF
statements on object if already in RDF (fedora-migrate)

23. Descriptive metadata to Fedora 4:
Option 2
• Map only simple statements to RDF
– Minimal descriptive metadata (title, date) or
descriptive metadata indexed for discovery (title,
date, creator, type, subject, genre, language)
– Use ontologies that allow for simple statements

25. Descriptive metadata to Fedora 4:
Option 2
• Map only simple statements to RDF
– Minimal descriptive metadata (title, date) or
descriptive metadata indexed for discovery (title,
date, creator, type, subject, genre, language)
– Use ontologies that allow for simple statements
Not all metadata is in RDF; changes in
ontologies/standards might not be 1:1 match with original
Creates RDF statements in Fedora 4/external triplestore; great
option if metadata is DC or other non-hierarchical standard

26. Descriptive metadata to Fedora 4:
Option 3
• Map complex/hierarchical information into
external triplestore
– All RDF statements (simple and complex) go into
external triplestore but only simple statements
are on Fedora 4 object

27. Cushman photograph – Fedora 4

28. Cushman photograph – external triplestore

29. Descriptive metadata to Fedora 4:
Option 3
• Map complex/hierarchical information into
external triplestore
– All RDF statements (simple and complex) go into
external triplestore but only simple statements
are on Fedora 4 object
Separates metadata between repository and triplestore,
problematic if original metadata not kept in repository
More/all metadata available as RDF; updates easier to manage
through triplestore/Fedora 4 functionality

30. Descriptive metadata to Fedora 4:
Almost Option 4
• MODS “unofficial standard” mapping to RDF
– MODS and RDF Group’s mapping/transformation
scenario (http://mods2rdf.xyz/)
– Available as conversion code to see MODS mapped
into Fedora 4
Work in progress (not always up, transforming few elements);
you might not agree with suggested mappings
Available now to try; might offer standard way to transform
MODS similarly across institutions

31. Considerations for descriptive
metadata
• Current state of descriptive metadata
• Management needs of Fedora 4
• Transform to RDF statements or also to Linked
Data
• Decision: keep original descriptive metadata
or not?
– At IU, keep original descriptive metadata (for full
item view)

32. Thank you!
• Julie Hardesty
• jlhardes@iu.edu
• @jlhardes