Ist16-03 An Introduction to the Semantic Web

E. Della Valle – http://emanueledellavalle.org - @manudellavalle

Interoperability and Semantic Technologies 2015-16An Introduction to the Semantic Web

Emanuele Della ValleDEIB - Politecnico di Milanohttp://emanueledellavalle.org - @manudellavalle


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IntroductionThe Web Today

3

Large number of integrations - ad hoc - pair-wise

Too much information to browse, need for searching and mashing up automatically

Each site is “understandable” for us

Computers don’t “understand” much

?

Search & Mash-up Engine

010 0 1 1 0

01101

10100 10 0010 01 101 101 01 110 1 10 110 0 1 1 01 0 1 0 0 1 1 0 1 1 1 10 01 101 0 1

Millions of Applications


IntroductionThe Problem: “Semantic Gap”

4

Sensor Data

Semantic Gap

Symbolic Description


Introduction “Understanding” Means Bridging the Gap

5

understanding

Sensor Data



IntroductionDo We Really Know What “Understanding” means?

6[ source http://www.thefarside.com/ ]

http://www.thefarside.com/


IntroductionTwo ways for computer to “understand”

7

Smart Data

Smart Machine


Working examples found on the WebImage Processing

retrievr: find by sketching

http://labs.systemone.at/retrievr/ Audio Processing

midomi: find by singing

http://www.midomi.com/

[…]

Natural Language Processingsemantic proxy: http://semanticproxy.opencalais.com/about.html

IntroductionSmart Machines

8

Sensor Data

Symbolic DescriptionIm

age

Proc

essi

ng

Aud

ioPr

oces

sing

Nat

ural

Lan

guag

e

Proc

essi

ng

[…]

http://labs.systemone.at/retrievr/

http://labs.systemone.at/retrievr/

http://semanticproxy.opencalais.com/about.html

http://semanticproxy.opencalais.com/about.html


Natural Language Processing (NLP) meets Image Processing (IP)

NLP: What does your eye see?IP : I see a seaNLP: You see a “c”?IP : Yes, what else could it be?

IntroductionSmart Machines alone cannot bridge the gap …

9

[Source NLP Related Entertainment http://www.cl.cam.ac.uk/Research/NL/amusement.html]

Sensor Data


Imag

e Pr

oces

sing

Nat

ural

Lan

guag

e

Proc

essi

ng

sea “c”

Semantic Gap

http://www.cl.cam.ac.uk/Research/%0BNL/amusement.html


Natural Language Processing (NLP) meets Image Processing (IP)

NLP: What does your eye see?IP : I see a wordnet:word-sea NLP: mmm, I see a wordnet:word-c IP : I believe we have different understanding of the world …NLP: So do I

Introduction… smart data are need

10

Sensor Data


Imag

e Pr

oces

sing

Nat

ural

Lan

guag

e

Proc

essi

ng

sea “c”

smart data

The Semantic Web offers a set of standards that lowers the barriers to

employ smart data at Web scale

http://wordnet.rkbexplorer.com/description/word-sea

http://wordnet.rkbexplorer.com/description/word-c


What we say to Web agents " For more information visit <a

href=“http://www.ex.org”> my company </a> Web site. . .”

What they “hear” " blah blah blah blah blah <a

href=“http://www.ex.org”> blah blah blah </a> blah blah. . .”

Jet this is enought to train them to achive tasks for us

IntroductionWhat a machine “understands” of the Web

11[ source http://www.thefarside.com/ ]

http://www.thefarside.com/


Understanding that[page1] links [page2] page2 is interesting

Google is able to rank results!“The heart of our software is PageRank™, a system for ranking

web pages […] (that) relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value.”

http://www.google.com/technology/

IntroductionWhat does Google “understand”?

12

http://www.google.com/technology/


“The Semantic Web is not a separate Web, but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation.”

“The Semantic Web”, Scientific American Magazine, Maggio 2001 http://www.sciam.com/article.cfm?articleID=00048144-10D2-1C70-84A9809EC588EF21

Key concepts• an extension of the current Web• in which information is given well-defined meaning • better enabling computers and people to work in

cooperation.• Both for computers and people

Introduction The Semantic Web 1/4

13


“The Semantic Web is not a separate Web, but an extension of the current one […] ”


14

Web 1.0 The Web Today


“The Semantic Web […] , in which information is given well-defined meaning […]”


15

Human understandable but “only” machine-

readable

Human and machine

“understandable”

?

Web 1.0 Semantic Web



16

Semantic Web

Fewer Integration - standard - multi-lateral

[…] better enabling computers and

people to work in cooperation.

Even More Applications

Easier to understand for people

More “understandable” for computers

Semantic Mash-ups &Search


Introduction Linked Data Standards

17

View the full talk at http://www.ted.com/talks/view/id/484 !


Goal: extend the Web with data commons by publishing open data sets using Semantic Web techs

Introduction Linking Open Data Project

Visit http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/LinkingOpenData !


Introduction Example: BIO2RDF

19

Peter Ansell, Model and prototype for querying multiple linked scientific datasets, Future Generation Computer Systems, Volume 27, Issue 3, March 2011, Pages 329-333


• is an effort to add a spatial dimension to theSemantic Web.

• uses the information collected by the OpenStreetMap project

• makes it available as an RDF knowledge baseaccording to the Linked Data principles.

• interlinks this data with other knowledge bases in the Linking Open Data initiative.

Introduction Example: LinkedGeoData

20


Introduction data.gov and data.gov.uk

21


Introduction https://open-data.europa.eu/en/data


• Who: Richard MacManus • When: April 15th, 2010• Context: Modigliani’s painting are

scattered all other the world• The challenge: If all museums would have

published their collections as linked data, will it be possible to know the locations of allthe original paintings of Modigliani?

• http://readwrite.com/2010/04/15/the_modigliani_test_semantic_web_tipping_point

Introduction The Modigliani test for Linked Data


<?xml version="1.0" encoding="utf-8"?> <rdf:RDF xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs = "http://www.w3.org/2000/01/rdf-schema#" xmlns:owl = "http://www.w3.org/2002/07/owl#" xmlns:dc = "http://purl.org/dc/elements/1.1/" xmlns:foaf = "http://xmlns.com/foaf/0.1/" xmlns:rel = "http://www.perceive.net/schemas/relationship/" xmlns:mo = "http://purl.org/ontology/mo/" xmlns:rev = "http://purl.org/stuff/rev#" > <rdf:Description rdf:about="/music/artists/a3cb23fc-acd3-4ce0-8f36-

1e5aa6a18432.rdf"> <rdfs:label>Description of the artist U2</rdfs:label> <foaf:primaryTopic rdf:resource="/music/artists/a3cb23fc-acd3-4ce0-8f36-

1e5aa6a18432#artist"/> </rdf:Description> <mo:MusicGroup rdf:about="/music/artists/a3cb23fc-acd3-4ce0-8f36-

1e5aa6a18432#artist"> <foaf:name>U2</foaf:name> <owl:sameAs rdf:resource="http://dbpedia.org/resource/U2" /> <foaf:page rdf:resource="/music/artists/a3cb23fc-acd3-4ce0-8f36-

1e5aa6a18432.html" /> <mo:musicbrainz rdf:resource="http://musicbrainz.org/artist/a3cb23fc-acd3-

4ce0-8f36-1e5aa6a18432.html" /> <mo:homepage rdf:resource="http://www.u2.com/" /> <mo:fanpage rdf:resource="http://www.atu2.com/" /> <mo:wikipedia rdf:resource="http://en.wikipedia.org/wiki/U2" /> <mo:imdb rdf:resource="http://www.imdb.com/name/nm1277752/" /> <mo:myspace rdf:resource="http://www.myspace.com/u2" /> <mo:member rdf:resource="/music/artists/7f347782-eb14-40c3-98e2-

17b6e1bfe56c#artist" /> <mo:member rdf:resource="/music/artists/1f52af22-0207-40ac-9a15-

e5052bb670c2#artist" />

Introduction Example: BBC’s Artist as Linked Data

24

HTML: http://www.bbc.co.uk/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432

RDF : http://www.bbc.co.uk/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432.rdf DISCONTINUED


The Results of Modigliani test for Linked Data• Who: Atanas Kiryakov (Ontotext AD)• When: April 25th, 2010• How: http://factforge.net/ a “reason-able” view to the web of data• Results: http://bit.ly/ModiglianiTest

http://readwrite.com/2010/04/25/the_modigliani_test_for_linked_data

Introduction The Modigliani test for Linked Data


•Since Fall 2009•450.000 products •Using RDFa (= RDF embedded in HTML)•Pages with RDFa higher in Google ranking•BestBuy claims 30% more traffic!•Yahoo reports 15% higher click-through rat

Introduction Example: Best Buy


© 2012 Politecnico di Milano, Emanuele Della Valle


<div rel="v:hasReview"><span property="v:rating" datatype="xsd:string"> 4.8</span> of <span property="v:best">5</span>

RDFa


Google for Nikon+12.3-Megapixel+Digital+SLR+Camerahttps://www.google.com/search?q=Nikon+12.3-Megapixel+Digital+SLR+Camera


enriche

d pages//28

Sponsored Links


Use RDFa with some FB specific vocabularyog:title - The title of your object, e.g., "The Rock".og:type - The type of your object, e.g., "movie". og:image - An image URL og:url - The permanent ID of your object og:description - A one to two sentence description of your object.og:site_name - If your object is part of a larger web site, the name which

should be displayed for the overall site. e.g., "IMDb".

Introduction Example: Facebook Open Graph

http://ogp.me/


Open Graph Usage Statistics15 millions sites are using Open Graph! 39% of the top 10,000 sites

Introduction Example: Facebook Open Graph

[Source: http://trends.builtwith.com/docinfo/Open-Graph-Protocol]

%

40

30

202010 2011 2012 2013 2014 2015


Introduction Industrial uptake of Semantic markup

2009/2010 winter-2014

147.871.837 urls 620.151.400 urls microformats 80% rdfa+microdata 80%[Source: http://webdatacommons.org/structureddata/index.html#results-2013-1 ]

80%

20%

10%


RDFa, microformats and "rich snippet" on Google trends

Take home message: data formats matter, but data usage matters even more!

Introduction Usage matters!

microformats

RDFa

Rich snippet


Introduction Usage matters! Yahoo! Search Monkey

[source https://developer.yahoo.com/searchmonkey/siteowner.html ]


Introduction Usage matters! Google structured data

Emanuele Della Valle -

@manudellavalle - http://emanueledellavalle.

org

[source https://developers.google.com/structured-data/rich-snippets/ ]


• Schema.org• an initiative launched on 2 June 2011 by Bing, Google and Yahoo! • to “create and support a common set of schemas for structured data

markup on web pages.”• Like microformats it is a collection of vocabularies, but they are organized

in a broad type hierarchy (like RDF-Schema)• See http://schema.org/docs/full.html

• Initially schema.org introduced yet another type of semantic markup (i.e., microdata), but it stepped back and it now recommends either microdata or RDFa

• Tools are available: http://schema.rdfs.org/tools.html

Introduction schema.org

Emanuele Della Valle -

@manudellavalle - http://emanueledellavalle.

org

enriched pages//35


There are around 1200 types in the hierarchy

[Sou

rce

http

://bl

og.s

chem

a.or

g/20

15/1

1/sc

hem

aorg

-wha

ts-n

ew.h

tml ]



Beyond rich snippet, into the Knowledge Graph



Introduction Semantic Web “layer cake”

38

Standardized

UnderInvestigation

Already Possible

[ source http://www.w3.org/2007/03/layerCake.png ]

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Ist16-03 An Introduction to the Semantic Web

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