brief introduction to linked data

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Rob Sanderson ([email protected]) -- Provenance Index Workshop

A Brief Introduction to Linked Data

http://www.getty.edu/art/collection/objects/11704/unknown-maker-euboean-black-figure-neck-amphora-greek-euboean-about-570-560-bc/

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Data Silo? “An insular management system incapable of

reciprocal operation with other, related information systems” :(Silos protect the data, but make it hard to get at. Technologists spend a lot of time designing very clever silos, that tend to keep the data very very safe … and very hard to get at.But it’s not the silo that’s the important thing we should be thinking about.

Our Data Lives in Silos

http://www.getty.edu/art/collection/objects/34108/bernd-and-hilla-becher-grain-elevator-elliott-illinois-usa-german-1982/

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Data We build lots of different types of silo, that serve the

same purpose – protecting the data – but all look and work very differently. Technologists get excited about new bigger, better silos … or even just different ones.

Actually … Water Towers (1963-1995) at San Francisco Museum of Modern Art this weekend.

In Many Silos

Becher photography at San Francisco Museum of Modern Art: https://www.sfmoma.org/artwork/FC.840.A-DD

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Data The data that we’re locking up inside them

is what’s important … not the ugly building we constructed to keep it in. We can’t let our grain sit in its silos until it rots away, or we all starve for lack of it.

Follower of the Egerton Master, about 1410, Man Pointing to Grain Stalks (leaf)

Data

http://www.getty.edu/art/collection/objects/3437/follower-of-the-egerton-master-a-man-pointing-to-grain-stalks-zodiacal-sign-of-leo-french-about-1410/

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Data So we build crazy contraptions on top of our data

silos to get the content back out again, adding more technology to solve the problem the first technology created. We try to move data from one silo to another, because it’s more convenient with other data. So we try to build bigger and bigger silos to hold more and more data. But the farm down the road still can’t get to our data, and we can’t get to theirs …

Data Elevators?

http://www.getty.edu/art/collection/objects/34108/bernd-and-hilla-becher-grain-elevator-elliott-illinois-usa-german-1982/

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Data Even when that data is about the same thing. Same

person, material, place, event. Black figure attic vases (amphorae), attributed to the same artist (The Affecter) in the British Museum, the Getty Villa, and the Louvre from left to right. Much prettier silos for wine, or grain!If only there was an information system that could take content from multiple, distributed institutions, and provide a way to link it together such that someone sitting on their couch when making slides for presentations could look up images of attic vases across three different countries …

Common Content

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The WebNo surprise … the web is the largest and most successful information system ever built. Many people have never lived without it (a scary thought, sorry). But while the web is good for humans with browsers, it’s incomprehensible to machines. So some people thought … what can we learn from how the web works, and apply it to our data such that it can be easily shared, accessed and understood? That led to the notion of Linked Data.

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So what /is/ the Web then? It’s pages with URLs, with interesting content

The Web: Pages with URLs…

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With links in that content

And Links…

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To other pages with more interesting content. And it’s important to note that what makes the web work is that the content might not be in the same web site.

To Go to More Pages

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So ... I have to tell you now, that you may have already been exposed to some Linked Data. That doesn’t look like Linked Data, you say? That’s just a screenshot of a web page… Well, what if I change the colors…

Data

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Better? Data is often represented as label and value – the creator is Affecter, the medium is Terracotta. Those labels and values are about the object.

Data

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We can then have different labels and values for different objects. Here’s Affecter.

Data

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DataRelational Data

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Why is the Web Successful?

• Identify things with URLs• Return useful information when you go to the URL• Link to other things with URLs• Common format for describing things–HTML on the Web, RDF for Data

• Easy for anyone to use• Easy for anyone to contribute

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Use URLs

• Thing described gets a URL as its identity• Get back the description when you go to that URL

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DataLink to Things

• Can link to our own things• Or other people’s things

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Data Should be Easy to Use

• Easy to understand data gets used• More usage, more links to it• More links, the more usage• More usage, the more reputation• More reputation, the more trust• More trust, the more usage

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Why Linked Data?

• Avoid conceit that our institution is the only one• We can’t know everything, but can link out

• Find new information for things we care about– Hidden across different institutions– Or within a single organization

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Why Linked Data?

• Easily discover objects with the same or related features [in different institutions]• Merge information from [different] trusted

institutions, saving time and money• Graph (like the web) more powerful than records

(like individual files)

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DataWhat’s Next?

Need critical mass of:• Data! (with links to other & others’ data)• Tools for creating and using the data• Understanding of the benefits, and challenges

Need to start somewhere, and make it easy to participate

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Current Challenge

• Linked Data relies on agreement about the meaning of links (hence Semantic Web)

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Conclusions

• Linked Data takes the best practices of the Weband applies them to Data• Use URLs for identity, give access to the raw data• Recognize that many people have something

valuable to say• Make data publicly available– Using standards– Consistently with others

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Thank You!

Rob [email protected]

@azaroth42

Further References:– https://www.w3.org/DesignIssues/LinkedData.html– https://www.ted.com/talks/tim_berners_lee_on_the_next_web– Linked Data: https://www.youtube.com/watch?v=4x_xzT5eF5Q– JSON-LD: https://www.youtube.com/watch?v=vioCbTo3C-4– http://www.slideshare.net/azaroth42/linked-data-building-standards-and-communities

Thanks to the IIIF Community, @manusporny for content inspiration.

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Masterclass: Distributed Identity

• Others also create URLs for the same thing–http://dbpedia.org/resource/Affecter–http://collection.britishmuseum.org/id/…

• Distributed datasets, connected via links• No blessed gatekeeper• Reconciliation:

Does URL-X identify the same thing as URL-Y?

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Linking for Reconciliation

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Danger! Danger!

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Linking for Reconciliation

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DataReconciliation…

• http://www.slideshare.net/azaroth42/linked-data-snowball-or-why-we-need-reconciliation

brief introduction to linked data

Art & Photos