Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Linked Data in Practice: Building Standards, Building Communities

Robert Sanderson rsanderson@lanl.gov // azaroth42@gmail.com // @azaroth42

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Overview

•  Standards •  Linked Data: Advantages and Challenges

•  Graph Structure •  Open World •  Ontologies and Identities •  Serialization Formats

•  Communities

WARNING: Packaged in a Factory Containing Controversy

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Standards

Standards are essential: Infrastructure like Electricity Like Electricity, there can be more than one but having

the adapters is always a pain Or Standards like USB...

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Building Standards

Standards are about agreement. Technical side is easy compared to getting community

engagement and support. (Much like herding cats)

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Building Web Standards

The web has revolutionized communication, especially scholarly communication. Any modern communication standard

needs to be a web standard Web Standards are about linking things together. Web Standards are about data. Linked Data is done using a Graph,

expressed in a technical framework called RDF

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Graphs

ü Graphs are very powerful for modeling reality ü  Tree (like XML) is just a simple Graph ü  Don’t end up in semantic/syntactic hell (like XML)

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Graphs: Structure and Data

Ø Working with graphs must take structure into account

Graph: Structure and Data important, but data currently treated as second class citizen Other: Only Data important, so easier to work with •  Can’t think about “documents” as all nodes/edges

are stored together

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Graphs: Structure and Data

Ø Visualization is difficult to get right Ø … and hard to know when it is right

Ø Documents “easy” to visualize

Ø Graph visualization almost universally terrible … because has to take structure into account

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Visualization Done Right

http://www.facebook.com/note.php?note_id=469716398919

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Not So Right

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Graphs

Other structures don’t get as complicated because they lack the expressiveness of a graph

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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The Open World

ü A Single Global Graph that everyone contributes to ü  Great for data re-use ü  Global identities ü  Richness of data from multiple sources ü  Distributed: Can incrementally add to others descriptions ü  Fits with the WWW: The Data Web

Technically: If a statement is not asserted, then its truth-value is

unknown, rather than false. Data: Painting has X’s signature Question: Does the painting have Y’s signature? Closed World: No Open World: I Don’t Know

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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The Open World: Global Identities

Jon publishes an Annotation about part of a web page.

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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The Open World: Global Identities

Brewster archives the page … and says where it is.

ü Without modifying the annotation at all!

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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The Open World: Local Complexity

Ø Every assertion is considered true in all contexts

Q: How do we say that Canvas 2 comes after Canvas 1, and Canvas 3 comes after Canvas 2?

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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The Open World: Ordering

Did you think this? Remember anyone can say anything, and it’s global…

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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The Open World: Ordering

Now there are two next links from Canvas 1, and our list is … a graph. Use Case: Manuscript has different page order at different times

Jane

Freya

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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The Open World: Ordering

ORE introduces proxy nodes, as not just order is local. Eg may wish to cite a resource in the context of a set of resources.

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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The Open World: Ordering

Shared Canvas uses multiple classes and the rdf:List construction. Serializations hide the list’s anonymous nodes.

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Local identity for local context is good practice!

The Open World

Think Globally Identify Locally

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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ü Shared relationships increase interoperability ü  dc:title is ‘name’ or ‘label’, not property title or Dr. ü  Re-use of semantics makes it easier to build applications ü  Communities can develop own ontologies of relationships

independently

ü Shared Identity makes it possible for graph to merge serendipitously ü  Everyone can mint own IDs using http URIs ü  By reusing ids, graphs will merge, creating new knowledge

Ontologies and Identities

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Ø “The nice thing about … Ontologies … is that there’s so many to choose from” Ø  Too many to choose from, hard to find the right one Ø  If almost right, do you reuse and hope for the best, or

specialize and create yet another ontology?

Ontologies and Identities

http://xkcd.com/927/

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Ø “The nice thing about … Identities … is that there’s so many to choose from” Ø  Far far too many to choose from, hard to find the right one Ø  As anyone can create identity for anything, they do Ø  Identity can have a contextual component – does LANL’s

identifier for Oppenheimer differ from DBPedia’s?

Ontologies and Identities

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Standards! Communities!

Ontologies and Identities

http://www.flickr.com/photos/clydeorama/6693882429/

House of Representatives from Huffington Post

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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ü The new JSON-LD format is pretty good

Serializations

{! "@context": "http://www.w3.org/ns/oa.json", ! "@id": "http://example.org/anno1", ! "@type": "oa:Annotation", ! "annotatedAt": "2012-11-10T09:08:07", ! "annotatedBy": {! "@id": "http://public.lanl.gov/rsanderson#me", ! "@type": "foaf:Person", ! "name": "Rob Sanderson"! }, ! “hasBody": {"chars": "This... is CNN.”}, ! “hasTarget": “http://www.cnn.com/”!}!

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Ø The recommended RDF/XML is absolutely terrible Ø  “RDF/XML was the Semantic Web’s 3 Mile Island incident”

-- Manu Sporny, http://manu.sporny.org/2012/nuclear-rdf/

Serializations

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Building Community is hard! •  W3C Community Groups •  Funding •  Engagement not Argument •  Early Embedding •  Merge when possible

Path may be longer together, but it’s better

Communities

Linked Data in Practice: Building Standards and Communities Yale Digital Collections Center, Nov 19 2013, New Haven CT, USA

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Slides: http://www.slideshare.net/azaroth42/

xxx-yyy Open Annotation: http://www.openannotation.org/

http://www.w3.org/community/openannotation/ Shared Canvas: http://www.shared-canvas.org/ http://iiif.io/

Rob Sanderson: rsanderson@lanl.gov // azaroth42@gmail.com @azaroth42 // http://public.lanl.gov/rsanderson/

Thank You!