Social Semantic Web. Semantic Web WS 2017/18. Anna Fensel 12/12/2017

Transcription

1 Semantic Web WS 2017/18 Social Semantic Web Anna Fensel Copyright Dieter Fensel, Katharina Siorpaes, and Anna Fensel 1 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 2 1

2 Agenda 1. Motivation 2. From Web to Web 2.0: Technical solution and illustrations 3. Social Semantic Web : Technical solution and illustrations 4. Summary 5. References MOTIVATION

3 Motivation 5 Motivation (cont d) 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

4 Social Network Facebook Facebook is a social networking service and website; Launched in February 2004 It is owned and operated by Facebook, Inc billion monthly active users as of June 30, 2015 * 1.31 billion mobile monthly active users as of June 30, 2015 * Users must register before using the services. Users can create a personal profile, add friends, exchange messages, chat (the company has also launched a separate instant messaging service), receive automatic notifications, take part in games, etc. * Wikipedia Motivation (cont d) 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 tics,

5 FROM WEB TO WEB 2.0: TECHNICAL SOLUTION AND ILLUSTRATIONS Web 1.0 to Web 2.0 Evolution Definition Applications and success stories Statistics to Web

6 Web 2.0 Web 2.0 is a notion for a row of interactive and collaborative systems of the internet What is the web 2.0? Definition by O Reilly Web 1.0 Web 2.0 improvement DoubleClick Google AdSense personalized Ofoto Flickr tagging, community Britannica Online Wikipedia community, free content Webseiten blogging dialogue publishing participation CMS wikis flexibility, freedom directories tagging community taxonomy folksonomy Consumers Prosumers

7 What is the Web 2.0? - Examples 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) 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)

8 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) Wikis: Design Principles Open Should a page be found to be incomplete or poorly organized, any reader can edit it as they see fit. Incremental Pages 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. Overt The formatted (and printed) output will suggest the input required to reproduce it. Source:

9 Tagging 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: Flickr.com

10 Collaborative Tagging Collaborative Tagging: Delicious Browser plug-ins available from 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

11 Folksonomies Data created by tagging, knowledge structures User Tag Resource User Tag Tag Resource Resource User Tag Tag Resource Resource Mary tags with wiki wikipedia encyclopedia Bob tags with wiki web2.0 encyclopedia knowledge 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)

12 Tag Clouds Size of Tags: count of usage Browsing replaces Searching Different meaning for different users Orientation in Information Set What is the Web 2.0? Trends for Web Applications 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)

13 Web 2.0 People, Services, Technologies 25 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,

14 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)

15 Blurring the distinction between content consumers and providers Interactive Web applications through asynchronous JavaScript and XML (AJAX) 29 Blurring the distinction between content consumers and providers: Weblogs or Blogs, Wikis

16 Blurring the distinction between content consumers and providers: Flickr, YouTube 31 Blurring the distinction between content consumers and providers Tagging del.icio.us, shazam.com

17 Blurring the distinction between content consumers and providers RDFA, micro formats 33 Moving from a media for individuals towards a media for communities Folksomonies, FOAF

18 Moving from a media for individuals towards a media for communities Community pages (friend-of-a-friend, flickr, LinkedIn, myspace, ) 35 Moving from a media for individuals towards a media for communities Second Life

19 Moving from a media for individuals towards a media for communities Wikipedia 37 Moving from a media for individuals towards a media for communities Wikipedia

20 Blurring the distinction between service consumers and service providers RSS feeds 39 Blurring the distinction between service consumers and service providers Yahoo pipes allow people to connect internet data sources, process them, and redirect the output

21 Blurring the distinction between service consumers and service providers Widgets, gadgets, and mashups Blurring the distinction between service consumers and service providers - Hands On: Twitter API Developer page: API start page:

22 Blurring the distinction between service consumers and service providers - Hands On: Twitter API Twitter widgets: direct homepage integration of twitter content 1. Login to own twitter account Create New Widget Integrating human and machine computing in a new way Amazon mechanical turk, Fiverr, etc

23 Integrating human and machine computing in a new way Human computing (captchas) 45 Integrating human and machine computing in a new way - Hands On: Facebook API Developer page: Products: Ad framework (Websites, Apps) Analytics App support Facebook Login Messaging Marketing Social Plugins Like, share, send, comment directly from own website Embedd Posts and videos in own website more

24 Social Media Monitoring SOCIAL SEMANTIC WEB: TECHNICAL SOLUTION AND ILLUSTRATIONS

25 Semantic Web + Web 2.0 = Web 3.0? Web 2.0 Web 3.0 Tagging Annotation with Tags Annotation with concepts Singular/Plural Problem Inference (Tag Dog --> Synonyms Tag Pet ) No Intelligence 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 Based on Völkl, Vrandecic and colleagues Web 3.0 Approaches 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)

26 Gartner Hype Curve Gartner, July Web 2.0 and the Semantic Web Web 2.0 and Semantic Web are complementary approaches 1. Semantic Blogging 2. Semantic Wikis Semantic MediaWiki 3. Web 2.0 ontology building myontology 4. Games for semantic content creation OntoGame

27 Semantic Blogging Creating blog entries in a structured fashion Based on ontologies This allows: Acquiring complementary information from the Web Finding blog entries better 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

28 Semantic Wikipedia: Advantages 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? Based on Völkl, Vrandecic and colleagues 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. Based on Völkl, Vrandecic and colleagues

29 Semantic MediaWiki Based on Völkl, Vrandecic and colleagues What is located in California? Based on Völkl, Vrandecic and colleagues

30 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) Ontology editor for Semantic MediaWiki Produced in ACTIVE project

31 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 The create functionalities-category Primary navigation Create functionalities Import functionalities Knowledge repair Media Wiki links Introduction Important links Content overview Tag Cloud

32 The create functionalities-category Input form Name Description Auto completion Entity creation Automatic annotations Overview page 63 The create functionalities-category Introduction Input fields Name Vocabulary SeeAlso Synonym Example Description Properties New ones Existing ones Supercategories Name analysis Help fields

33 Knowledge repair-cycles, links, names 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 65 Knowledge repair-cycles, links, names Tab repair Repair of a specific category Explanations Tables with numerical values Paragraphs and lists

34 Knowledge repair-cycles, links, names 67 myontology Collaborative creation of ontologies A tool which helps specialists and ontology experts to collaborate easily MyOntology uses the Web 2.0 paradigm

35 myontology Philosophy 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 Games for semantic content creation Design A prerequisite for the Semantic Web to become a reality is the availability of annotated data. Maintenance Building the Semantic Web is not a one-time task, but a continuous effort

36 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 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

37 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 Challenges 1. Identifying suitable tasks in semantic content creation 2. Designing games 3. Designing a usable, attractive interface 4. Identifying suitable knowledge corpora 5. Preventing cheating 6. Defusing typical pitfalls of conceptual modeling 7. Distribution of labor 8. Fostering user participation 9. Deriving formal representations 10. Scalability and performance

38 TheOntoGame Series 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

39 OntoPronto: Creating a Huge Domain Ontology OntoTube: Annotating YouTube videos

40 SUMMARY 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, however, often at an expense of loss of privacy resulting from sharing of the data. Social Semantic Web approaches combile parts of Web 2.0 with semantics. Examples include Semantic Wikis, Semantic blogs, games for semantic content creation, etc. The information solicited with Web 2.0 is accessible in the semantic way via SPARQL endpoints, APIs e.g. Google Knowledge Graph Search, Facebook Graph Search, etc

41 REFERENCES References Mandatory reading:

42 References Further reading: Auer, S., Bizer, C., Müller, C., Zhdanova, A.V. (Eds.), The Social Semantic Web, Bonner Köllen Verlag, Lecture Notes in Informatics (LNI), Vol. 113, September S. Braun, A. Schmidt, A.Walter, G. Nagypal, and V. Zacharias. Ontology maturing: A collaborative web 2.0 approach to ontology engineering, May S. E. Campanini, P. Castagna, and R. Tazzoli. Platypus wiki: a semantic wiki wiki web. pages 16, December Peter Mika. Ontologies are us: A unified model of social networks and semantics. volume LNCS Springer, S. Schaffert. Ikewiki: A semantic wiki for collaborative knowledge management. June K. Siorpaes, M. Hepp, A. Klotz, and M. Hackl. myontology: Tapping the wisdom of crowds for building ontologies. Technical report, STI Innsbruck Technical Report, K. Siorpaes and M. Hepp. Games with a purpose for the semantic web. IEEE Intelligent Systems, 23(3):5060, M. Völkel, M. Krötzsch, Denny Vrandecic, and H. Haller. Semantic wikipedia. May 23-26, References Wikipedia links:

43 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 85 Questions?