Semantic Social NetworksSemantic Social Networks

Semantic Web Course, Fall 2005Semantic Web Course, Fall 2005

Computer Engineering DepartmentComputer Engineering Department

Sharif University of TechnologySharif University of Technology

Presented by Behrad ZariPresented by Behrad Zari

zari@ce.sharif.eduzari@ce.sharif.edu

OutlineOutline

IntroductionIntroductionSocial Network AnalysisSocial Network Analysis

MetricsMetrics User RelationshipsUser Relationships User ContextUser Context

Putting Semantics into WorkPutting Semantics into WorkThe FOAF: Friend Of A FriendThe FOAF: Friend Of A Friend

What FOAF Does?What FOAF Does? Creating FOAF documentsCreating FOAF documents FOAF VocabularyFOAF Vocabulary

Applications of InterestApplications of InterestRelated TopicsRelated TopicsReferencesReferences

Sharif University of Technology,Semantic Web Course, Fall 2005

IntroductionIntroduction

The Internet has become a rich and large repository of The Internet has become a rich and large repository of information about individuals.information about individuals.

The links and text on a user's homepage to the mailing The links and text on a user's homepage to the mailing lists the user subscribes to are reflections of social lists the user subscribes to are reflections of social interactions a user has in the real world.interactions a user has in the real world.

The high quality information we discover provides a The high quality information we discover provides a glimpse into the social life of two communities and has glimpse into the social life of two communities and has potential applications in automatically inferring real-world potential applications in automatically inferring real-world connections and discovering and labeling communities.connections and discovering and labeling communities.

Social NetworksSocial Networks are topics of our interest. are topics of our interest.

Sharif University of Technology,Semantic Web Course, Fall 2005

Social Network AnalysisSocial Network Analysis

Obtaining data requires time consuming phone or live interviews.

We are able to harvest this information easily and automatically with Social Network Analysis.

This presents an unprecedented opportunity to discover new and interesting social and cultural phenomena.

Reveal densely connected clusters or communities of Reveal densely connected clusters or communities of practice.practice.

Sharif University of Technology,Semantic Web Course, Fall 2005

MetricsMetrics

Activity:Activity: Behrad is a Behrad is a connectorconnector with 6 direct links with 6 direct links to other nodes.to other nodes.

Betweenness:Betweenness: Kiumars has only 3 connections Kiumars has only 3 connections but holds a powerful position as the sole but holds a powerful position as the sole boundaryboundary spannerspanner between different groups. between different groups.

Closeness:Closeness: Yasser and Kiumars have the Yasser and Kiumars have the shortest paths to all others. They have an shortest paths to all others. They have an excellent view of what's going on.excellent view of what's going on.

Sharif University of Technology,Semantic Web Course, Fall 2005

User User Relationships (1) (1)

There are four sources of information for a user, in-links and mailing lists which are provided by external sources, and out-links and text which are provided by the users themselves.

All four can be used as a means of inferring relationships between the users.

Sharif University of Technology,Semantic Web Course, Fall 2005

User User Relationships (2) (2)

The text on user’s home page provides semantic insight into the content of a user’s page. Co-occurrence of text (we actually use multi-word “things” such as organization names, noun phrases, etc. instead of single word text) between users who link to each other usually indicates a common interest.

Out-links are links from a user's homepage to other pages.

In-links are links from other pages to the user's homepage. For example, a list of all members of a fraternity will link to individual homepages.

Mailing Lists provide us with valuable community structure that may not necessarily appear in homepage based communities.

Sharif University of Technology,Semantic Web Course, Fall 2005

User ContextUser Context

Different ways we can collect data to set a context for a user:

Words and phrases the user mentions on their homepage.

Links included in the user's homepage. External links to the user's homepage. Mailing lists the user belongs to.

Sharif University of Technology,Semantic Web Course, Fall 2005

Putting Semantics into WorkPutting Semantics into Work

Social Network Analysis researches use text mining tools Social Network Analysis researches use text mining tools and graph mining algorithms to find knowledge about and graph mining algorithms to find knowledge about some social network characteristics.some social network characteristics.

Creating a machine processable web of data by Creating a machine processable web of data by expressing metadata about people and their social expressing metadata about people and their social interactions.interactions.

Semantic Personal Homepages:Semantic Personal Homepages: My name is Behrad, this is a picture of me, I'm interested in My name is Behrad, this is a picture of me, I'm interested in

Semantic Web, and here are some links to my friends.Semantic Web, and here are some links to my friends.

Sharif University of Technology,Semantic Web Course, Fall 2005

The FOAF: Friend Of A FriendThe FOAF: Friend Of A Friend

A A SemanticWebSemanticWeb project started at 1999 project started at 1999

An RDF vocabulary for expressing metadata An RDF vocabulary for expressing metadata about people, and their interests, relationships about people, and their interests, relationships and activities.and activities.

RDF based:RDF based: Can be easily harvested and aggregated.Can be easily harvested and aggregated. Can be easily combined with other vocabularies.Can be easily combined with other vocabularies.

Sharif University of Technology,Semantic Web Course, Fall 2005

What FOAF Does?What FOAF Does?

Machines can answer questions like:Machines can answer questions like: Show me pictures of bloggers interested in Show me pictures of bloggers interested in

(foo) who live near me.(foo) who live near me. Show me recent articles written by people at Show me recent articles written by people at

this meeting.this meeting. Is this person vegetarian?Is this person vegetarian?

Syndicating Syndicating yourselfyourself to others. (just like to others. (just like what RSS does for your blog)what RSS does for your blog)

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Creating FOAF DocumentsCreating FOAF Documents

FOAF-a-MaticFOAF-a-Matic:: HTML & Javascript HTML & Javascript

FOAF FOAF CreatoCreato:: XForms XForms

Sharif University of Technology,Semantic Web Course, Fall 2005

FOAF VocabularyFOAF Vocabulary

Namespace URI: Namespace URI: http://xmlns.com/foaf/0.1http://xmlns.com/foaf/0.1

Main Categories:Main Categories: FOAF BasicsFOAF Basics Personal InfoPersonal Info Online Accounts / IMOnline Accounts / IM Projects and GroupsProjects and Groups Documents and ImagesDocuments and Images

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FOAF Vocabulary: BasicsFOAF Vocabulary: Basics

AgentAgent PersonPerson namename nicknick titletitle homepagehomepage mboxmbox mbox_sha1summbox_sha1sum imgimg depictiondepiction ( (depictsdepicts) ) surnamesurname family_namefamily_name givennamegivenname firstNamefirstName

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A Basic ExampleA Basic Example

<foaf:Person><foaf:Person>

<foaf:name>Behrad Zari</foaf:name> <foaf:name>Behrad Zari</foaf:name> <foaf:mbox>zari@ce.sharif.edu</foaf:mbox><foaf:mbox>zari@ce.sharif.edu</foaf:mbox>

<foaf:homepage <foaf:homepage rdf:resource="http://www.xyz.ir/jrad"/>rdf:resource="http://www.xyz.ir/jrad"/>

<foaf:img<foaf:img rdf:resource="http://www.xyz.ir/rdf:resource="http://www.xyz.ir/jrad/pic-small.jpeg"/>jrad/pic-small.jpeg"/>

</foaf:Person></foaf:Person>

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FOAF Vocabulary: Personal InfoFOAF Vocabulary: Personal Info

weblogweblog knowsknows interestinterest currentProjectcurrentProject pastProjectpastProject planplan based_nearbased_near workplaceHomepageworkplaceHomepage workInfoHomepageworkInfoHomepage schoolHomepageschoolHomepage topic_interesttopic_interest publicationspublications myersBriggsmyersBriggs dnaChecksumdnaChecksum

Sharif University of Technology,Semantic Web Course, Fall 2005

FOAF Vocabulary: Online Accounts FOAF Vocabulary: Online Accounts

OnlineAccountOnlineAccount OnlineChatAccountOnlineChatAccount OnlineEcommerceAccountOnlineEcommerceAccount OnlineGamingAccountOnlineGamingAccount holdsAccountholdsAccount accountServiceHomepageaccountServiceHomepage accountNameaccountName icqChatIDicqChatID msnChatIDmsnChatID aimChatIDaimChatID jabberIDjabberID yahooChatIDyahooChatID

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FOAF Vocabulary: Projects and FOAF Vocabulary: Projects and GroupsGroups

ProjectProject

OrganizationOrganization

GroupGroup

membermember

membershipClass membershipClass

fundedBy fundedBy

theme theme

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FOAF Vocabulary: Documents and FOAF Vocabulary: Documents and ImagesImages

Document Document Image Image PersonalProfileDocument PersonalProfileDocument topic (page) topic (page) primaryTopic primaryTopic tipjar tipjar sha1 sha1 made (maker) made (maker) thumbnail thumbnail logo logo

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Expressing RelationshipsExpressing Relationships<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-

syntax-ns#" xmlns:foaf="http://xmlns.com/foaf/0.1/" syntax-ns#" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">

<foaf:Person rdf:nodeID=“behrad"> <foaf:Person rdf:nodeID=“behrad"> <foaf:name>Behrad Zari</foaf:name> <foaf:name>Behrad Zari</foaf:name>

</foaf:Person> </foaf:Person> <foaf:Person> <foaf:Person>

<foaf:name>Kiumars Sh. E.</foaf:name> <foaf:name>Kiumars Sh. E.</foaf:name> <foaf:knows rdf:nodeID=“behrad"/> <foaf:knows rdf:nodeID=“behrad"/> <foaf:knows> <foaf:knows>

<foaf:Person><foaf:Person><foaf:name>Y. Ganji</foaf:name> <foaf:name>Y. Ganji</foaf:name>

</foaf:Person></foaf:Person></foaf:knows></foaf:knows>

</foaf:Person></foaf:Person></rdf:RDF></rdf:RDF>

Sharif University of Technology,Semantic Web Course, Fall 2005

Finer-grained RelationshipsFiner-grained Relationships

FriendOf, EnemyOf, ChildOf, ParentOf:FriendOf, EnemyOf, ChildOf, ParentOf:<foaf:Person rdf:ID=“gg"> <foaf:Person rdf:ID=“gg"> <foaf:name>Games Gosling</foaf:name> <foaf:name>Games Gosling</foaf:name> <rel:enemyOf rdf:resource="#bill-<rel:enemyOf rdf:resource="#bill-gates"/>gates"/>

</foaf:Person> </foaf:Person> <foaf:Person rdf:ID=“jb"> <foaf:Person rdf:ID=“jb"> <foaf:name>Jusha Bloch</foaf:name> <foaf:name>Jusha Bloch</foaf:name> <rel:friendOf rdf:resource="#gg"/><rel:friendOf rdf:resource="#gg"/>

</foaf:Person> </foaf:Person>

Sharif University of Technology,Semantic Web Course, Fall 2005

IdentificationIdentification

There is no There is no rdf:aboutrdf:about attribute on the attribute on the foaf:Personfoaf:Person resource: resource:

<foaf:Person rdf:about="uri to identify peter"/><foaf:Person rdf:about="uri to identify peter"/>

Which URI identifies you?Which URI identifies you?Who assigns these URIs? Who assigns these URIs? How to handle multiple URIs?How to handle multiple URIs?

FOAF borrows the concept of an FOAF borrows the concept of an inverse functional propertyinverse functional property (IFP) from OWL. (IFP) from OWL.

Sharif University of Technology,Semantic Web Course, Fall 2005

Identification (2)Identification (2)

The FOAF schema defines several inverse functional properties, The FOAF schema defines several inverse functional properties, including:including:

foaf:homepagefoaf:homepage foaf:mboxfoaf:mbox foaf:mbox_sha1sumfoaf:mbox_sha1sum

Sample:Sample: <foaf:Person> <foaf:Person>

<foaf:name>Behrad Zari</foaf:name> <foaf:name>Behrad Zari</foaf:name> <foaf:mbox_sha1sum>cf2f4bd069302febd8d7c26d803f63fa7f20bd82<foaf:mbox_sha1sum>cf2f4bd069302febd8d7c26d803f63fa7f20bd82</foaf:mbox_sha1sum></foaf:mbox_sha1sum>

</foaf:Person> </foaf:Person>

<foaf:Person> <foaf:Person> <foaf:name>Jrad</foaf:name> <foaf:name>Jrad</foaf:name> <foaf:mbox_sha1sum>cf2f4bd069302febd8d7c26d803f63fa7f20bd82<foaf:mbox_sha1sum>cf2f4bd069302febd8d7c26d803f63fa7f20bd82</foaf:mbox_sha1sum> </foaf:mbox_sha1sum>

</foaf:Person></foaf:Person>

Sharif University of Technology,Semantic Web Course, Fall 2005

RDF HyperlinksRDF Hyperlinks

As in HTML you can link foaf documents to each other to build an As in HTML you can link foaf documents to each other to build an association.association.

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"> xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">

<foaf:Person rdf:nodeID=“behrad"> <foaf:Person rdf:nodeID=“behrad"> <foaf:name>Behrad Zari</foaf:name> <foaf:name>Behrad Zari</foaf:name>

<rdfs:seeAlso rdf:resource="http://www.xyz.ir/behrad.rdf"/><rdfs:seeAlso rdf:resource="http://www.xyz.ir/behrad.rdf"/> </foaf:Person> </foaf:Person>

<foaf:Person> <foaf:Person> <foaf:name>Kiumars Sh. E.</foaf:name> <foaf:name>Kiumars Sh. E.</foaf:name> <foaf:knows rdf:nodeID=“behrad"/> <foaf:knows rdf:nodeID=“behrad"/> </foaf:Person> </foaf:Person>

</rdf:RDF> </rdf:RDF>

Sharif University of Technology,Semantic Web Course, Fall 2005

Applications of InterestApplications of Interest

Applications of Semantic Web technology Applications of Semantic Web technology for social collaborative software:for social collaborative software:

Blogs: Semantic BloggingBlogs: Semantic Blogging Wikis: Semantic WikisWikis: Semantic Wikis Social Semantic DesktopSocial Semantic Desktop Visualizing Semantic NetworksVisualizing Semantic Networks

Sharif University of Technology,Semantic Web Course, Fall 2005

Related TopicsRelated Topics

Social Network Analysis of the Semantic WebSocial Network Analysis of the Semantic WebAnalysis of Large Online Communities (Wikipedia, DMOZ, EBay, ...)Analysis of Large Online Communities (Wikipedia, DMOZ, EBay, ...)Semantic Web CommunitiesSemantic Web CommunitiesOnline Harvesting of Semantic Network InformationOnline Harvesting of Semantic Network InformationEmergent Semantics in CommunitiesEmergent Semantics in CommunitiesSelf-organization and Management of Semantic NetworksSelf-organization and Management of Semantic NetworksTrust Issues in Semantic NetworksTrust Issues in Semantic NetworksSemantic Network MetadataSemantic Network MetadataOnline Social Networking (FOAF, Orkut, ...)Online Social Networking (FOAF, Orkut, ...)Applications of Online Semantic NetworksApplications of Online Semantic NetworksKnowledge Management with Semantic NetworksKnowledge Management with Semantic Networks

Sharif University of Technology,Semantic Web Course, Fall 2005

ReferencesReferences[1] Stefania Ghita, Wolfgang Neidl and Raluca Paiu, Semantically Rich [1] Stefania Ghita, Wolfgang Neidl and Raluca Paiu, Semantically Rich

Recommendations in Socal Networks for Sharing and Exchanging Semantic Recommendations in Socal Networks for Sharing and Exchanging Semantic Context, L3S Research Center, University of Hanover.Context, L3S Research Center, University of Hanover.

[2] John C. Paolillo and Elijah Wright, Social Network Analysis on the Semantic [2] John C. Paolillo and Elijah Wright, Social Network Analysis on the Semantic Web: Techniques and Challenges for Visualizing FOAF.Web: Techniques and Challenges for Visualizing FOAF.

[3] Lada A. Adamic and Eytan Adar, Friends and Neighbors on the Web[3] Lada A. Adamic and Eytan Adar, Friends and Neighbors on the Web

[4] FOAF Vocabulary Specification, [4] FOAF Vocabulary Specification, http://xmlns.com/foaf/0.1/http://xmlns.com/foaf/0.1/, 27 July 2005, 27 July 2005

[5] FOAF WIKI, [5] FOAF WIKI, http://http://rdfweb.org/topic/FoafProjectrdfweb.org/topic/FoafProject

[6] Finding friends with XML and RDF by Edd Dumbill 01 Jun 2002[6] Finding friends with XML and RDF by Edd Dumbill 01 Jun 2002

[7] An Introduction to FOAF by [7] An Introduction to FOAF by Leigh Leigh DoddsDodds February 04, 2004 February 04, 2004

Sharif University of Technology,Semantic Web Course, Fall 2005

Questions?Questions?

Thank You!Thank You!

Sharif University of Technology,Semantic Web Course, Fall 2005