semantic web

www.sti-innsbruck.at 1© Copyright 2010 Dieter Fensel and Katharina Siorpaes

Semantic Web

Social Semantic Web

www.sti-innsbruck.at 2

Where are we?

# Title

1 Introduction

2 Semantic Web Architecture

3 Resource Description Framework (RDF)

4 Web of data

5 Generating Semantic Annotations

6 Storage and Querying

7 Web Ontology Language (OWL)

8 Rule Interchange Format (RIF)

9 Reasoning on the Web

10 Ontologies

11 Social Semantic Web

12 Semantic Web Services

13 Tools

14 Applications


Agenda

1. Motivation2. From Web to Web 2.0: Technical solution and illustrations3. Social Semantic Web : Technical solution and illustrations4. Summary5. References

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MOTIVATION

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Motivation

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• Information Sharing: – Image sharing: Flickr– Video sharing: YouTube– Online encyclopedia: Wikipedia– Blogs: eblogger– Open Source Community: Linux

• File Management– Tagging: Delicious

• Social Websites and Communication:

Facebook LastFM Skype StudiVZ LinkedIn, Xing

• Open Systems: APIs, partly open source allow extensions by users

Motivation (cont‘d)

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Internet platform for creation of social networks

• More than 400 million active users • 50% of our active users log on to Facebook in any given day • More than 35 million users update their status each day • More than 60 million status updates posted each day • More than 3 billion photos uploaded to the site each month • More than 5 billion pieces of content (web links, news stories, blog

posts, notes, photo albums, etc.) shared each week • More than 3.5 million events created each month • More than 3 million active Pages on Facebook • More than 1.5 million local businesses have active Pages on

Facebook

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http://www.facebook.com/press/info.php?statistics, 17.2.2010


Wikipedia

Free Online Encyclopedia• 3,197,507 Articles (english Wikipedia)• 11,693,499 registered contributors• Clever mechanisms combined with human intelligence• High quality articles• Self-organized control• Semi-openess


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http://en.wikipedia.org/wiki/Wikipedia:Statistics, 17.2.2010


FROM WEB TO WEB 2.0: TECHNICAL SOLUTION AND ILLUSTRATIONS

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Web 1.0 to Web 2.0

• Evolution

• Definition

• Applications and success stories

• Statistics to Web 2.0

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Web 2.0

“Web 2.0 is a notion for a row of

interactive and

collaborative systems of the

internet“

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http://widgets-gadgets.com/2006_10_01_archive.html


Consumers Prosumers

Web 1.0 Web 2.0 improvement

DoubleClick Google AdSense personalizedOfoto Flickr tagging, communityBritannica Online Wikipedia community, free

contentWebseiten blogging dialoguepublishing participationCMS wikis flexibility, freedomdirectories tagging community taxonomy folksonomy

What is the web 2.0? „Definition“ by O‘Reilly

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• Gmail• Google Documents (Collaborative Notepad in the Web)• Wikis• Wikipedia

– Worlds biggest encyclopedia, Top 30 web site, 100 langueges

• Del.icio.us (Social Tagging for Bookmarks)• Flickr (Photo Sharing and Tagging) • Blogs, RSS, Blogger.com• Programmableweb.com (APIs)

What is the Web 2.0? - Examples

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Blogs

• Easy usable user interfaces to update contents

• Easy organization of contents

• Easy usage of contents

• Easy publishing of comments

• Social: collaborative (single users but strongly connected)

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Wikis

• Wiki invented by Ward Cunningham• Collection of HTML sites: read and edit• Most famous and biggest Wiki: Wikipedia (MediaWiki)

– But: Also often used in Intranets (i. e. our group)

• Problems solved socially instead of technically• Flexible structure• Background algorithms + human intelligence• No new technologies• social: collaborative (nobody owns contents)

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Source: http://c2.com/cgi/wiki?WikiDesignPrinciples

• Open Should a page be found to be incomplete or poorly organized, any reader can edit it as they see fit.

• IncrementalPages can cite other pages, including pages that have not been written yet.

• Organic The structure and text content of the site are open to editing and evolution.

• Mundane A small number of (irregular) text conventions will provide access to the most useful page markup.

• Universal The mechanisms of editing and organizing are the same as those of writing so that any writer is automatically an editor and organizer.

• OvertThe formatted (and printed) output will suggest the input required to reproduce it.

Wikis: Design Principles

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• Idea: Enrich contents by user chosen keywords

• Replace folder based structure by a organisation using tags

• New: Simple user interfaces for tagging and tag based search

• First steps to Semantic Web?

• Technically: user interfaces

• Social: collaborative (own contents, shared tags)

Tagging

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Tagging: Flickr.com

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Collaborative Tagging

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Collaborative Tagging: Delicious

• Browser plug-ins available from http://del.icio.us• Allows the tagging of bookmarks• Community aspect:

– Suggestion of tags that were used by other users– Availability of tag clouds for bookmarks of the whole community– Possibility to browse related bookmarks based on tags

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Folksonomies

User Tag Resource

Resource

Resource

Resource

Resource

Tag

Tag

Tag

Tag

User

User

Mary tags www.wikipedia.org with wiki wikipedia encyclopedia

Bob tags www.wikipedia.org with wiki web2.0 encyclopedia knowledge

Data created by tagging, knowledge structures

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Folksonomies: Taxonomie Marlow et al. (2006)

• Rights for Tagging– Self-tagging: Contents only tagged by owner (Technorati)– Free-for-all tagging: Tagging by all users (Yahoo!)

• Support of Tagging– Blind Tagging: Existing Tags are not displayed (Flickr)– Viewable Tagging: Existing Tags are displayed (Del.icio.us)– Suggestive Tagging: Suggestions for Tags (MyWeb 2.0)

• Aggregation of Tags– Bag-model: Multiple entries (Del.icio.us)– Set-model: Only single entries (YouTube)

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Tag Clouds

Size of Tags: count of usage

Orientation in Information Set

Browsing replaces

Searching

Different meaning for

different users

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• Technical Evolution– Web User Interfaces become faster (AJAX)– Desktop shifts to Web (GMail, Google Notebooks, AJAX)

• Social Evolution– Collective creates additional value (Wiki, Tagging)– Free contents become popular (Licenses)– Attention is getting monetarized (Text-Ads)– Websites with additional value by recombination (Mash-Ups, RSS)

What is the Web 2.0? Trends for Web Applications

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Web 2.0

People, Services, Technologies


Web 2.0

• Web 2.0 is a vaguely defined phrase referring to various topics such as social networking sites, wikis, communication tools, and folksonomies.

• Tim O'Reilly provided a definition of Web 2.0 in 2006: "Web 2.0 is the business revolution in the computer industry caused by the move to the internet as platform, and an attempt to understand the rules for success on that new platform. Chief among those rules is this: Build applications that harness network effects to get better the more people use them."

• Tim BL is right that all these ideas are already underlying his original web ideas, however, …


Web 2.0

The four major breakthroughs of Web 2.0 are:1. Blurring the distinction between content consumers and content

providers.

2. Moving from media for individuals towards media for communities.

3. Blurring the distinction between service consumers and service providers.

4. Integrating human and machine computing in a new way.


Blurring the distinction between content consumers and providers

Interactive Web applications through asynchronous JavaScript and XML (AJAX)



Interactive Web applications through asynchronous JavaScript and XML (AJAX)


Blurring the distinction between content consumers and providers:

Weblogs or Blogs, Wikis


Blurring the distinction between content consumers and providers:

Flickr, YouTube



Tagging – del.icio.us, shazam.com



RDFA, micro formats


Moving from a media for individuals towards a media for communities

Folksomonies, FOAF



Community pages (friend-of-a-friend, flickr, LinkedIn, myspace, …)



Second Life



Wikipedia


Blurring the distinction between service consumers and service providers

RSS feeds



Yahoo pipes allow people to connect internet data sources, process them, and redirect the output.



Widgets, gadgets, and mashups.


Integrating human and machine computing in a new way

Amazon Mechanical turk


Integrating human and machine computing in a new way

Human computing (captchas)


SOCIAL SEMANTIC WEB:TECHNICAL SOLUTION AND ILLUSTRATIONS

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Semantic Web + Web 2.0 = Web 3.0?

Based on Völkl, Vrandecic and colleagues.

Web 2.0 Web 3.0

Tagging Annotation with Tags Singular/Plural Problem Synonyms No Intelligence

Annotation with concepts Inference (Tag „Dog“ -->

Tag „Pet“)

Recombination of data from different sources

• Mash-Ups developed earlier by programmer

• Spontaneous by End User

Search • Keyword Search or Tag Search finds documents

• Structured Search combines Data und creates documents

Period • 2004 - 2007 • 2007 – 2010

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• Automatic Extraction of knowledge based on large (and free) sets of data, generated by Web 2.0

• Integration and Reuse of knowledge (Yahoo Pipes)• Motivate users for generating semantic contents by using Web 2.0

paradigms• Creation of Semantic as side effect of working processes (semantic

wikis)

Web 3.0 Approaches

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Gartner Hype Curve

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Gartner, July 2007


Web 2.0 and Semantic Web are complementary approaches

1. Semantic Blogging2. Semantic Wikis

• Semantic MediaWiki

3. Web 2.0 ontology building• myOntology

4. Games for semantic content creation• OntoGame

Web 2.0 and the Semantic Web

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Semantic Blogging

• Creating blog entries in a structured fashion• Based on ontologies• This allows:

– Acquiring complementary information from the Web– Finding blog entries better

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Semantic Wikis

• A semantic wiki is a wiki that has an underlying model of the knowledge described in its pages.

• Regular, or syntactic, wikis have structured text and untyped hyperlinks. • Semantic wikis, on the other hand, allow the ability to capture or identify

information about the data within pages, and the relationships between pages, in ways that can be queried or exported like database data.

• Wikis:– Platypus wiki– IkeWiki– Kiwi– WikiFactory– Semantic MediaWiki

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Structured Knowledge can be exported (in RDF)

• New Web 2.0 Applications are possible

• Reusing of knowledge beyond languege borders

• Aggregated Search over more than one site

• Quality: Finding of mistakes and conflicts– Has every country a capital city?– Is every person born before dying?– Does the population density match to population and area?

Semantic Wikipedia: Advantages

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Semantic Wiki = Wiki + Semantic Web


• Semantic MediaWiki: Extension of the MediaWiki Software

• Syntax extension allows typed links• Page Karlsruhe

– Up to now: … in the south of [[Germany]] …– Now: … in the south of [[is in::Germany]] …

• Syntax extension allows annotaion of values• Page Karlsruhe

– Up to now: … has a population of 280,000 people. …– Now: … has a population of [[population:=280000]]

people.

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Semantic MediaWiki


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What is located in California?


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Web 2.0 ontology building

• Make use of various Web 2.0 paradigms to capture knowledge required for ontologies

• Lower entrance barriers for users• Usually emphasis on collaboration• Ontologies as community contracts• Methods for consensus finding• Visualization of ontologies• Examples:

– Ontology editor based on SMW– Myontology– Soboleo (image annotation)

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Ontology editor for Semantic MediaWiki

• http://smw-active.sti-innsbruck.at

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Semantic Media Wiki – Ontology Editor

• Ontology Element Management

– Management of vocabularies, categories, properties, and elements

– Enhanced user interface: tagcloud, forms, tree-view

– Enriched content through external media (e.g. Flickr)

• Knowledge Repair

– Statistical analysis of knowledge within the wiki

– Detection and correction of inconsistencies

– Discovery of redundancies

• Knowledge Import

– Folksonomy import through mapping to the SKOS ontology

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•Primary navigation•Create functionalities•Import functionalities•Knowledge repair•Media Wiki links

•Introduction

•Important links

•Content overview

•Tag Cloud

The create functionalities-category


•Input form•Name•Description

•Auto completion

•Entity creation

•Automatic annotations

•Overview page



•Introduction•Input fields

•Name•Vocabulary•SeeAlso•Synonym•Example•Description

•Properties•New ones•Existing ones

•Supercategories•Name analysis•Help fields



•Comprehensive overview

•Table with explanations

•Table with min, avg, max values

•Table with results for each category

•Colored cells and symbols to indicate probable issues

Knowledge repair-cycles, links, names


•Tab ´repair´

•Repair of a specific category

•Explanations

•Tables with numerical values

•Paragraphs and lists



myOntology

• Collaborative creation of ontologies

• A tool which helps specialists and ontology experts to collaborate easily

• MyOntology uses the Web 2.0 paradigm

www.myontology.org

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• Collaboration of specialists and ontology experts• In first phase (until lightweight ontologies) • High usability• Integration and Reusing of web knowledge (Web 2.0: Folksonomies,

Flickr, YouTube, Wikipedia, etc.)• „Background intelligence“ supports development team

myOntology Philosophy

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Games for semantic content creation

Ontology Alignment

OntologyConstruction

Semantic Annotation ...

Maintenance

Design

A prerequisite for the Semantic Web to become a reality is the availability of annotated data.

Building the Semantic Web is not a one-time task, but a

continuous effort.

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Observation

There are tasks that are easy for humans but difficult for computers

Cf. Von Ahn

Not all the tasks on the Semantic Web can be automated.

Some at least partly require human intelligence.

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Web 2.0 is Hot, Semantic Web is Not. Why?

• Web 2.0 applications enjoy great popularity

• The incentive structures are clear (Marlow et al.,2006;

Kuznetsov, 2004)

• Incentives for ontology building, ontology alignment, and semantic annotation

have not been investigated so far

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The OntoGame Idea and Principles

Make people weave the Semantic Web by playing cool multi-player online games.

1. Fun and intellectual challenge

2. Consensus

3. Massive content generation

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10 Challenges

1. Identifying suitable tasks in semantic content creation2. Designing games 3. Designing a usable, attractive interface 4. Identifying suitable knowledge corpora 5. Preventing cheating 6. Defusing typical pitfalls of conceptual modeling7. Distribution of labor 8. Fostering user participation 9. Deriving formal representations 10. Scalability and performance

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TheOntoGame Series

Weaving the Semantic Web

by Online Gaming

Step 1: Build and Maintain Semantic Web Vocabularies

SpotTheLink: Aligning UNSPSC and eCl@ss

OntoPronto: Linking Wikipedia / DBPedia

URIs to PROTON

OntoTube: Annotating YouTube Videos

OntoBay: Annotating eBay Offerings

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Features

• Players paired randomly and anonymously• Best strategy to get points: truthful answers• Live mode, single player mode, chess mode

(remote)• Skip• Limited amount of time• Cheating:

– Anonymity– Pre-recorded challenges

• Generic gaming platform • Derive formal representations of the data

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OntoPronto:Creating a Huge Domain Ontology


OntoTube: Annotating YouTube videos


SUMMARY

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Summary

• The Web has undergone change from „Web 1.0“ to „Web 2.0“.• Web 2.0 stands for more user interaction, the change from consumers

to prosumers, the programmable Web, collaboration, easy interfaces, etc.

• This movement has triggered enormous user participation. Many tools provide strong incentives to their users.

• Social Semantic Web approaches aim at combining parts of Web 2.0 with semantics.

• Examples including Semantic Wikis, Semantic blogs, games for Semantic content creation, etc.

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REFERENCES

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References

• Mandatory reading:– http://oreilly.com/web2/archive/what-is-web-20.html

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References

• Further reading:– http://social.semantic-web.at/index.php/Main_Page– S. Braun, A. Schmidt, A.Walter, G. Nagypal, and V. Zacharias. Ontology maturing: A

collaborative web 2.0 approach to ontology engineering, May 8 2007.– S. E. Campanini, P. Castagna, and R. Tazzoli. Platypus wiki: a semantic wiki wiki web.

pages 16, December 10 2004.– Peter Mika. Ontologies are us: A unied model of social networks and semantics. volume

LNCS 3729. Springer, 2005.– S. Schaffert. Ikewiki: A semantic wiki for collaborative knowledge management. June 2006.– K. Siorpaes, M. Hepp, A. Klotz, and M. Hackl. myontology: Tapping the wisdom of crowds

for building ontologies. Technical report, STI Innsbruck Technical Report, 2008.– K. Siorpaes and M. Hepp. Games with a purpose for the semantic web. IEEE Intelligent

Systems, 23(3):5060, 2008.– M. Völkel, M. Krötzsch, Denny Vrandecic, and H. Haller. Semantic wikipedia. May 23-26,

2006.

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References

• Wikipedia links:– http://en.wikipedia.org/wiki/Social_Semantic_Web– http://en.wikipedia.org/wiki/Web_2.0

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Next Lecture

# Title

1 Introduction

2 Semantic Web Architecture

3 Resource Description Framework (RDF)

4 Web of data

5 Generating Semantic Annotations

6 Storage and Querying

7 Web Ontology Language (OWL)

8 Rule Interchange Format (RIF)

9 Reasoning on the Web

10 Ontologies

11 Social Semantic Web

12 Semantic Web Services

13 Tools

14 Applications


Questions?