DLF 2015 Presentation, "RDF in the Real World."

RDF in the Real World

Lessons in Morphing MetadataJuliet L. Hardesty @jlhardes

Metadata Analyst, Indiana University LibrariesDigital Library Federation Forum 2015, Vancouver, BC

The conversation I want to have todayLibraries, archives, and museums deal with metadata A LOT

XML/text files, database tables

Tech we use has figured out how to do things with metadata in those formats

ILS, CMS, digital repositories, flesh & blood programmers \o/ :)

There’s more to this conversationRDF holds a lot of promise

How much is still just promise and how much is reality?

I have my perspective which includes a lot of Fedora 4

This is what I see and what I think we should understand as the library community

Different RDF activities are differentPublish Linked Data

RDF doesn’t have to be Linked Data

Software incorporates RDF for metadata

Digital object management through RDF graphs

Sharing metadata vs digital asset management

Resource Description Framework (RDF)It’s a way to model data:

subject -> predicate -> object .

a thing -> has property -> value of that property .

image has creator person .

<URI for image> <URI for term “creator”> <URI for person> .

REsource Description Framework (RDF)

http://id.loc.gov/authorities/names/no2004088188

http://purl.dlib.indiana.edu/iudl/archives/cushman/P13713

http://purl.org/dc/elements/1.1/creator

has creator

Women in several reds Hilton Hotel. July 14, 1964. Cushman, Charles W., 1896-1972

What RDF is doingDescribing resource (image)

Providing data (relationships and values)

Creating statements

eXtensible Markup Language (XML)<mods>

<identifier>P13713

<location><url>

http://purl.dlib.indiana.../P13713.jpg

<name><namePart>s

Cushman, Charles Weever, 1896-1972

<role><roleTerm>

photographer

.jpg

.xml

What XML is doingDescribing resource (image)

Labeling information (P13713)

Creating a document (record)

Fedora 4Expresses properties about digital objects using RDF

PCDM managing relationships between objects

Portland Common Data Model, Duraspace Github Wiki

RDF properties work unless things get complex

NOT MODS

Valid but complex RDF (statements wrapped inside statements)

subject predicate object1

1subject predicate object;subject predicate object;subject predicate object.

Here’s how things get complex

MODS RDF is currently complex hierarchical RDF

Fedora 4 creates blank nodes for complex RDF

These genres (Academy Award winner and Documentary films) become their own objects in Fedora

Here’s what Fedora 4 does with that

Here’s what’s been happeningGroup within Hydra community working through MODS elements

to find simpler ontology options to express descriptive information (DCTerms, MarcRelator, EDM, SKOS)

MODS and RDF Descriptive Metadata Subgroup - Hydra - DuraSpace Wiki

Steven Anderson at Boston Public Library leading effort

Providing feedback to MODS RDF Ontology group (version 2 in progress!)

PBCore XML + EBUCore RDF = PBUCore (?) RDFXML standard managed by WGBH (Boston again!)

Want to express PBCore XML in RDF to allow for descriptive and technical metadata statements in RDF in Fedora 4

Working with EBUCore to compare PBCore elements, establish which can be expressed with EBUCore classes and properties, and added some additional properties

Expanding expressions in EBUCore and allows PBCore XML to be transformed into RDF

UNLVUNLV started from CONTENTdm

Publishing LOD sets with interface to follow

UNLV Libraries

UCSDStarting with MODS

Complex records so created new data model

Mapping first to local identifiers then figuring out external URIs

Not keeping original MODSUCSD Geisel Library

http://library.ucsd.edu/ontology/dams

Oregon Digital and U AlbertaBringing various collections with various metadata together (silos!)

Wanted to create metadata as Linked Data in new DAMS (Fedora 4/Hydra)

http://oregondigital.org

https://era.library.ualberta.ca

So you have XML for metadata. How do you make it RDF?Develop use cases for why RDF is necessary

What metadata is RDF-ready (expressable as RDF) and how will RDF be used?

If XML doesn’t contain URIs (Linked Data-ready) can it be converted?

If XML standard is available as RDF (DC, DWC), transform XML and see what RDF looks like

Consider if RDF can be used as defined in use cases

So you are an XML standard. How do you make yourself RDF?Develop use cases for why RDF is necessary

Possible path: Create RDF ontology equivalent of XML

DC, DWC, MODS, VRA Core

Possible path: Integrate with an RDF ontology

PBCore XML to EBUCore RDF, with additional properties

Consider if RDF can be used as defined in use cases

Dodge, Mary Elizabeth. 1894. When Life is Young: a collection of verse for boys and girls. [p.] 143. The British Library. https://flic.kr/p/hXAC1A

CHALLENGES FROM XML TO RDFXML schema != RDF ontology

XML encodes information about something (<xml>info</xml>)

RDF statements are the information (info)

Hang in There by jurvetson https://flic.kr/p/7PuQdb

RDF ChallengesRDF ontology or mult RDF ontologies != All your metadata

RDF != Linked Data

NO, It Wasn’t Squirrel Proof !!! by kaceyhttps://flic.kr/p/65uX3J

Bibliography2015. “Descriptive Metadata Call 2015-06-24.” Descriptive Metadata Call 2015-06-24 - Hydra - DuraSpace Wiki. June 24. https://wiki.duraspace.org/display/hydra/Descriptive+Metadata+Call+2015-06-24.

Berners-Lee, Tim. 2009. “Linked Data.” Linked Data - Design Issues. June 18. http://www.w3.org/DesignIssues/LinkedData.html.

Estlund, Karen, and Tom Johnson. 2013. “Link It or Don’t Use It: Transitioning Metadata to Linked Data in Hydra,” July. http://ir.library.oregonstate.edu/xmlui/handle/1957/44856.

Farnel, Sharon. 2015. “Metadata at a Crossroads: Shifting ‘from Strings to Things’ for Hydra North.” presented at the Open Repositories, Indianapolis, Indiana. http://slideplayer.com/slide/5384520/.

Lampert, Cory K., and Silvia B. Southwick. 2013. “Leading to Linking: Introducing Linked Data to Academic Library Digital Collections.” Journal of Library Metadata 13 (2-3): 230–53. doi:10.1080/19386389.2013.826095.

Southwick, Sivlia B. 2015. “A Guide for Transforming Digital Collections Metadata into Linked Data Using Open Source Technologies.” Journal of Library Metadata 15 (1): 1–35.

Thanks!Julie Hardesty, Metadata AnalystIndiana University Librariesjlhardes@iu.edu@jlhardes