Semantic Web 2.0: Creating Social Semantic Information Spaces

Semantic Web 2.0: Creating Social Semantic Information Spaces John Breslin, Stefan Decker {john.breslin, stefan.decker}@deri.org http://sw.deri.org/~jbreslin/ http://www.stefandecker.org/ WWW2006 Tutorial Edinburgh, 26 th May 2006

0. Overview of this tutorial Semantic Web 2.0: Creating Social Semantic Information Spaces

Abstract (1) This tutorial will give an overview of current proposals in the Semantic Web area for adding semantics to emerging Web 2.0 applications and established communications media such as blogging, wikis, and bulletin boards We will also cover the usage of Semantic Web technologies for community portals We will discuss current standardisation activities as well as research prototypes

Abstract (2) Additional topics to be covered include semantic search based on metadata and large scale data integration as well as semantics in digital libraries Finally, we will discuss and present current approaches to realise the ideas of Vannevar Bush and Doug Engelbart on distributed collaboration infrastructures, which we term Social Semantic Information Spaces

Aims and objectives of this tutorial Aims: To teach you about applications of Semantic Web technologies to the areas of collaboration / communication systems, Web 2.0 and social software To describe SW applications in areas such as: semantics blogs interconnecting community sites semantic search semantic wikis on the Web or desktop information spaces Objectives: You will be able to apply Semantic Web technologies to various application areas in “Social Semantic Information Spaces”

Why is this topic relevant? (1) The Semantic Web is increasingly aiming at applications areas Web 2.0 applications such as blogging and wikis have become very popular and at the same time have created an interconnected information space (through the “blogosphere” and inter-wiki links) At the same time, these applications are experiencing boundaries in terms of information dissemination and automation , as they require increased levels of automation (i.e. more automated ways for information distribution)

Why is this topic relevant? (2) Quite a number of Semantic Web approaches have recently appeared to overcome the boundaries these application areas, e.g., Semantic Wikis , Semantic Desktops , etc. A recent Knowledge Web project meeting highlighted the importance of overlapping technologies between Web 2.0 and the Semantic Web

Your knowledge background If you have a background knowledge in the area of the Semantic Web: This tutorial will help you to develop application knowledge in relation to social software and other widely-used related web technologies If you have application knowledge in web engineering or the development of systems such as wikis and blogs: This tutorial will aid you in developing and creating ideas on how to increase the usability of social software and other web systems using Semantic Web technologies

Table of contents State of the Art in Semantic Web The Path Ahead for Social Semantic Information Spaces From Blogging to Semantic Blogging From Wikis to Semantic Wikis Semantic Search Semantics in Digital Libraries Semantics in Community Portals Realising the Memex and NLS: From the Desktop and Web to Social Semantic Information Spaces

1. State of the Art in Semantic Web Semantic Web 2.0: Creating Social Semantic Information Spaces

“ An extension of the current Web in which information is given well-defined meaning, better enabling computers and people to work in cooperation.” Sir Tim Berners-Lee et al., Scientific American, 2001: tinyurl.com/i59p “… allowing the Web to reach its full potential…” with far-reaching consequences “ The next generation of the Web” What is the Semantic Web?

Where are we in the “Semantic Web layer cake”? You Are Here!

The current (syntactic / structural) Web HTTP protocol is used for accessing and exchanging web data HTML language is used for creating web pages Resources are identified by URLs/URIs Untyped hyperlinks are used for “weaving the Web” together This has built an exciting multimedia world for users But there is very little information for machines

Was the Web meant to be more? In the original Web, Tim Berners-Lee had originally wanted something else as well: “ Information Management: A Proposal”, Tim Berners-Lee, CERN, March 1989/May 1990 Objects related by well defined attributes Web of relationships amongst named objects, yielding unified information management tasks Add metadata describing both structure and content

Sentences like these in red can be understood by people But how can they be understood by computers? The word “semantic” stands for “the meaning of” The semantics of something is the meaning of something The Semantic Web is a Web that is able to describe things in a way that computers can understand: The Beatles were a popular band from Liverpool John Lennon was a member of the Beatles The record "Hey Jude" was recorded by the Beatles Hence, the Semantic Web…

Describing things on the Semantic Web (1) RDF (Resource Description Framework) is an open format markup language for describing information and resources, and is the fundamental data model for the Semantic Web Using RDF, we can describe relationships between things like: A is a part of B or Y is a member of Z and their properties (size, weight, age, price…) in a machine-understandable format where each thing has a URI

Describing things on the Semantic Web (2) Its graph-based model means that it is straightforward for computers to process RDF data Putting information into RDF files makes it possible for “ scutters ” or RDF crawlers to search, discover, pick up, collect, analyse and process information from the Web

A simple RDF example Statement: “ Ora Lassila is the creator of the resource (web page) http://www.w3.org/Home/Lassila” Structure: Resource (subject) http://www.w3.org/Home/Lassila Property (predicate) http://www.schema.org/#Creator Value (object) “Ora Lassila” Directed graph: http://www.w3.org/Home/Lassila s:Creator Ora Lassila

Simple RDF example shown in RDF/XML In the directed graphs, the arrows point from the subject to the object, and the text on the arrow is the predicate The ellipses are resources and the rectangles are literals or text strings We can also represent this graph model in RDF/XML: <rdf:Description about=“ http://www.w3.org/Home/Lassila ”> <Creator> Ora Lassila </Creator> </rdf:Description>

Expanding on the previous example To add properties to the “Creator”, point through an intermediate resource (the ellipses are resources and the rectangles are literals or text strings): http://www.w3.org/Home/Lassila s:Creator Person://fi/654645635 Name Ora Lassila [email_address] Email

Expanded RDF example shown in RDF/XML <rdf:Description about=“ http://www.w3.org/Home/Lassila ”> <Creator rdf:resource=“ Person://fi/654645635 ”/> </rdf:Description> <rdf:Description about=“ Person://fi/654645635 ”> <Name> Ora Lassila </Name> <Email> [email_address] </Email> </rdf:Description>

Why does RDF make sense? A global environment needs a globally-agreed upon way to: Name things Relate to things RDF: Provides both these requirements Is the least common denominator

Can already describe lots of things semantically Geographic coordinates: GEO Library books: Dublin Core (DC) Online discussions: SIOC People, social networks: Friend-of-a-Friend (FOAF) Maybe even hormones! GeneOnt

The power of the Semantic Web Interoperability and increased connectivity is possible through a commonality of expression Vocabularies can be combined and used together : e.g. a description of a book using Dublin Core metadata can be augmented with specifics about the book author using the Friend-of-a-Friend vocabulary Vocabularies can be easily extended (modules, etc.) Intelligent search with more granularity and relevance: e.g. a search can be personalised to an individual by making use of their identity and relationship information

The challenge for the Semantic Web The Semantic Web can’t work all by itself: If it did it would be called the “Magic Web” It will need some help to become a reality For example, it is not very likely that you will be able to sell your car just by putting your RDF file on the Web Need society-scale applications: Consumers and processors of Semantic Web data Semantic Web agents or services More advanced collaborative applications that make real use of shared data and annotations

2. The Path Ahead for Social Semantic Information Spaces Semantic Web 2.0: Creating Social Semantic Information Spaces

The path to Semantic Web 2.0 The Semantic Web effort is mainly towards producing standards and recommendations that will interlink applications The Web 2.0 meme (next slide) is about providing user applications Not mutually exclusive: http://www.oreillynet.com/xml/blog/2005/10/is_web_20_killing_the_semantic.html With a little effort, many Web 2.0 applications can and do use Semantic Web technologies to great benefit We will now discuss Web 2.0 and describe what happens when we combine it with the Semantic Web

What is Web 2.0? The term Web 2.0 was made popular by Tim O’Reilly: http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html http://en.wikipedia.org/wiki/Web_2.0 “ Web 2.0 … has … come to refer to what some people describe as a second phase of architecture and application development for the World Wide Web.” The Web where “ordinary” users can meet, collaborate, and share using whatever is newly popular on the Web (tagged content, social bookmarking, AJAX, etc.) Popular examples include: Bebo, del.icio.us, digg, Flickr, Google Maps, Skype, Technorati, Wikipedia…

Web 2.0 and social software Web 2.0 focuses include: The Web as a platform for social and collaborative exchange Reusable community contributions Subscriptions to information, news, data flows, services Mass-publishing using web-based social software http://en.wikipedia.org/wiki/Social_Software “ Social Software lets people rendezvous, connect or collaborate by use of a computer network. It results in the creation of shared, interactive spaces…” Social software for communication and collaboration: IM, IRC, Forums, Blogs, Wikis, Social Network Services, Social Bookmarks, MMOGs…

From Web 1.0 to 2.0 (updated from O’Reilly) Tagging, Folksonomies Directories, Taxonomies Knowledge Syndication Stickiness Referencing BitTorrent, P2P Akamai Content Upcoming.org Evite Events Wikipedia Britannica Online Encyclopedi æ Skype, Asterisk Netmeeting Talk Google Services, AJAX, Flock Netscape, Internet Explorer Platforms Wikis Content Management Systems Portals Blogs Personal Websites Web Pages Web 2.0 Web 1.0

Elements of Web 2.0 (from Dion Hinchcliffe)

What are tagging and folksonomies? Tag: A keyword which acts like a subject or category Folksonomy: A collaboratively generated, open-ended labeling system that enables Internet users to categorise content using tags: Web links and pages (e.g. del.icio.us) using “social bookmarking” Online photographs (e.g. Flickr, Zooomr) Events (e.g. Upcoming.org) Blog entries, etc. Tag cloud: A visual depiction of the tags used on a website: Equivalent to a weighted list in the field of visual design

Folksonomies and the Semantic Web Folksonomies may hold the key to developing the Semantic Web Adding metadata can dramatically improve the precision (the percentage of relevant documents) in search engine retrieval lists Hard to persuade web authors to add metadata to their pages in a consistent, reliable way ( high entry costs , time consuming ): Few web authors make use of the simple Dublin Core metadata system, even though the use of DC meta tags could increase their pages' prominence in search engine retrieval lists In contrast to top-down controlled vocabularies, folksonomies are a distributed classification system with low entry costs If folksonomy capabilities were built into web protocols, possible that the Semantic Web would develop more quickly…

Metaweb  social semantic information spaces

From Web 1.0 to Semantic Web 2.0 Semantic Social Networks Online Social Networks Buddy Lists, Address Books Semantic Social Information Spaces … … Semantic Digital Libraries Google Scholar, Book Search CiteSeer, Project Gutenberg Semantic Forums and Community Portals Community Portals Message Boards Semantic Blogs Blogs Personal Websites Semantic Search Google Personalised, DumbFind Altavista, Google Semantic Wikis Wikis Content Management Systems Semantic Web 2.0 Web 2.0 Web 1.0

Example of how Web 2.0 is creating new synergies Scuttle + Gregarius + Feedburner + Grazr = … http://bonhom.ie/2006/04/what-weeks-delay-can-produce.html A hybrid that allows one to aggregate one’s favourite blogs or other content on a particular topic and then to annotate bookmarks to the most interesting content found

Hypothetically adding semantics to the example “ A semantic social collaborative resource aggregator ”: Okay, it needs a better name, like scraggy or something  Social network members specify their favourite content sources You and your friends specify any topics of interest You specify friends whose topic lists you value Metadata aggregator collects content from sites you and friends like (which may be human tagged, or could be auto-tagged) Highlights content that may be of interest to you or your friends If nothing of interest is currently available, content sources may have semantically-related sources in other communities for secondary content acquisition and highlighting You bookmark and tag the interesting content, and share !

1+1>2 Semantic forums Semantic blogs Semantic wikis Semantic social nets Semantic desktop Semantic Web + social software > sum of its parts

Social semantic information spaces: SW 2.0 Web 2.0 and social software

3. From Blogging to Semantic Blogging Semantic Web 2.0: Creating Social Semantic Information Spaces

A phenomenon for a new generation? Cincinnati Enquirer, October 2004

What are blogs? Weblog , web log or simply a blog A web application which contains periodic time-stamped posts on a common (usually open-access) webpage Individual diaries -> arms of political campaigns, media programs and corporations (e.g. the Google Blog) Posts are often shown in reverse chronological order Comments can be made by the public on some blogs Latest headlines, with hyperlinks and summaries, are syndicated using RSS or Atom formats (e.g. for reading favourite blogs with a feed aggregrator or reader )

The state of the “blogosphere” Source: Technorati (March 2003 to January 2006)

Some statistics from Technorati The blogosphere is 60 times greater than it was only 3 years ago 75,000 weblogs are created daily A new blog is created every second 13.7 million bloggers or ~50% are still posting 3 months after their blog is created 10% of all blogs update at least weekly About 9% of new blogs are spam!

From websites to blogs to semantic blogs… We will now discuss how personal websites have moved from ordinary blogs to semantic structured blogging platforms, using: Syndication formats and blog tags Structured input mechanisms Semantic Web technologies

Syndication of blog content (1) Syndication is used for publishing new content regularly Content is provided from many blogs and news sites in a common format that can be reused by other websites and applications in a “syndication” process Rather than mass-spamming via e-mail, interested parties can subscribe to feeds to be notified about changes or updates to information ( self service !) A common syndication format can have many uses , including connecting services together, “mashing” together of data, etc.

Syndication of blog content (2) More than just blog headline syndication, since RSS can be used for: Newspaper articles (one of the original usages) , library updates, recipes, shared calendars (RSSCalendar.com) , podcasts, videos, job posts, weather reports, financial updates, bug reports, wiki page changes, new photo uploads, forum thread replies, etc. Syndication format for blogs is usually RSS (although some sites now use different syndication formats, e.g. Blogger.com uses Atom )

Blog aggregators and readers Syndicated content allows one to check multiple feeds on a regular basis using aggregators or feed readers: Previously, semi-regular visits to bookmarked sites Feeds of syndicated content can now be pulled into readers Also, intelligent pushing of feeds (e.g. with “ pingback ”)

What is RSS? The most common syndication format(s) Acronyms: “ Really Simple Syndication” “ Rich Site Summary” “ RDF Site Summary Eight “flavours”: Not including Atom!

RSS 1.0 RSS 1.0 is in RDF (preferred format for Semantic Web as it can be used in conjunction with other ontologies) Class “channel”: Property “title” Property “link” Property “description” Property “items” (rdf:Seq) … Class “item”: Property “title” Property “link” Property “description” …

What is Atom? Another syndication system Based on XML (not RDF), but efforts towards AtomOWL Emphasis has shifted from the format to the API Specification: Constructs: content, people, dates and links Elements: feeds, with entries http://www.atomenabled.org/developers/syndication/atom-format-spec.php http://www.atomowl.org/

Linking blog posts by topic tags Blog posts are often categorised (e.g., “Scotland”, "Movies”) by the post creator Those on similar topics can be grouped together, using: Freetext tags or keywords Hierarchical tree categories For example, Technorati tags or keywords: Tags are category names, for people to categorise blog posts, photos, links, etc. Technorati.com wants to build a “tagged” web Utilising SW technology, can create categories using the SKOS vocabulary: http://www.wasab.dk/morten/blog/archives/2004/09/01/skos-output-from-wordpress http://www.w3.org/2004/02/skos/

Tags and related tags across blogs

Towards structured blogging? In structured blogging, packages of structured data are becoming post components The virtue of blogs has been their simplicity At the moment, each blog post only needs one field for content, and maybe a title and URL Not everyone is served well by this lowest common denominator Therefore the “Structured Blogging” working group was established last year: http://www.structuredblogging.org/

Structure-enhanced blog posts Sometimes you have a burning need for more structure, at least some of the time When you know a subject deeply, and your observations or analysis recur, you may be best served by filling in a form The form will have its own metadata and its own data model Uses: People get to express themselves, and Blogs start to interoperate with enterprise applications

Soccer coach example An after-game soccer report typically includes: which teams played where and when officials, and a list of game events: who scored (and when and how) who received penalties (when and for what), etc. Wouldn't it be handy for the coach’s blogging tool to understand this structure, present an editing form, render the form in HTML to their blog, and render the post (including the form) to their RSS feed? Great for the forthcoming World Cup!

Structured blogging using WordPress

Integrating readers with structured blogging And in the future, news aggregators and news readers should be able to: Auto-discover an unknown structure Notify the user that a new structure is available Learn the structure, including entry forms, pick list sources, rendering guidance, and default style sheet Make it available when the blogger is ready to write

Past and future structured blogging Past: Qlogger: http://www.qlogger.com/ Lafayette Project: http://www.megnut.com/weblogs/002594.asp JemBlog: http://ideagraph.net/jemblog/ Future: The Structured Blogging movement has previously focused on single-user blogging platforms: Should target multi-user blogging platforms like WPMU, B2Evolution or Drupal for more exposure http://www.johnbreslin.com/blog/2006/05/17/how-to-make-stuctured-blogging-popular/ Use Semantic Web technologies to ontologise any available post structures for more linkage and reuse

Traditional blogging vs. semantic blogging Traditional blogging: Publishing for the “eyeball Web” Content is text, images, video (i.e. data targeted at people) Semantic blogging: Enrich traditional blogs with semantic metadata Structural : what relates to what and how? Content related : what is this post about (e.g. a person, an event, etc.)? Blogging targeted at machines as well as people

Why semantic blogging? (1) Traditional blogging: Little or no query possibilities (except keyword and flat tags) Little or no reuse of data (except textual copy and paste) Little or no linking between posts (except simple hrefs and trackbacks) Semantic blogging: Facilitates better querying : More precise Allows aggregation from various sources Better reuse potential Richer links

Why semantic blogging? (2) Users collect and create large amounts of structured data on their desktops This data is often tied to specific applications and locked within the user's computer Semantic blogging can lift this data into the Web

Releasing your data to the Web scenario Ina John Ina‘s Computer John‘s Computer Blog Post Blog Post Blog Post Blog Post Metadata Metadata Metadata writes Post annotates Post publishes Post reads Post imports metadata Web

Positioning of the metadata Where in the blog will the semantic metadata go? Directly in the HTML ? Validity problems, parsing, restrictions on use of RDF... Put it in the newsfeed (RSS 1.0)? Would have to change blogging platforms, hard to get accepted Newsfeed items disappear over time Externally? Just add a link to HTML á la: <a type=“application/rdf+xml“ href=“http://bresl.in/foaf/foaf.rdf“>John</a>

How is this related to structured blogging? Structured blogging is mainly based on “Microformats” (http://www.microformats.org/) Therefore restricted to specific schemata, not open Positioned inline on HTML page (and in feed) Can be directly rendered using CSS Structured and semantic blogging do not compete Metadata can be added as RDF and using Microformats Web-based implementations for generating structured blogging metadata e.g. for WordPress and Movable Type

Creating the metadata (1) Structural metadata : Relations within the blogosphere: what relates to what and how (replies, follow-ups or trackbacks, blogroll links and bookmarks, topics, etc.)? Closed domain, suggested vocabulary: SIOC (more later!) Plugins for blogging platforms, e.g. WordPress, Drupal Produced automatically from a blog’s database

Creating the metadata (2) Content related metadata : What do blog posts talk about (e.g. books, individuals, meetings)? Keep open domain – so that can use any vocabulary / ontology (BibTeX, FOAF, iCal, ...) Web-based approach (á la structured blogging) - user fills in an HTML form Desktop-based approach (á la semiBlog) - user selects existing data on their computer, this gets converted into RDF

Creating a semantic blog post with semiBlog Annotating a blog entry with an address book entry. < foaf:Person rdf:ID="andreas"> < foaf:homepage > http://sw.bla.org/~aharth/</ foaf:homepage > < foaf:surname >Harth</ foaf:surname > < foaf:firstName >Andreas</ foaf:firstName >  < rdf:value >Andreas Harth</ rdf:value > </ foaf:Person >

External Applications (Address Book, Calendar, etc.) Publishing semiBlog architecture overview

Using the metadata Once a blog has semantic metadata, it can be... Used to query : “Which blog posts talk about papers by Stefan Decker?” Used to browse across blogs and other kinds of discussion methods: We will talk about this in more detail in section 7: “Semantics in Community Portals” Imported into desktop applications of blog readers (AKA “The Web as a Clipboard“)

The Web as a clipboard using a semiBlog reader A user can import metadata from here into his/her own applications

Semantic blogging with Haystack (1)

Semantic blogging with Haystack (2)

HP semantic blogging demonstrator http://www.semanticblogging.org/ “ Semantic view, semantic navigation and semantic query”

Semblog publishing platform (2)

Have described several applications and projects about semantic metadata for the blogosphere, e.g.: semiBlog produces semantic metadata for the blogosphere. … other approaches… Karger and Quan, Haystack, 2004 Cayzer, Semantic Blogging, 2004 Takeda and Ohmukai, Semblog, 2004 But what about a more general, higher-level look at the domain? How can we describe metadata in the blogosphere, what are the general categories? How does this effect implementation approaches? Need some approach at conceptualising metadata in the blogosphere More about metadata in the blogosphere

Structural metadata: Relations between blogs, posts, comments, etc. More than just “A links to B“ - what kind of relationship? Approval? Criticism? Mentions? Is about? … relations within the blogosphere Content-related metadata: What is this post about, what is its topic? Anything a blog author wishes to discuss ...relations between the blogosphere and everything else Structural versus content-related

Closed-domain metadata: The domain is restricted to a certain set of real-world entities or concepts, e.g. blog structure or scientific publications. Allows the definition of one specific domain ontology (e.g. SIOC) Open-domain metadata: The domain is not restricted, e.g. as in blog content Hard to define one all-embracing ontology, very unwieldy, hard to convince people to use it Instead divide into closed subdomains , use small, vertical domain ontologies (e.g. FOAF, BibTeX, etc.) Closed domain versus open domain

Client-side metadata: Data to be used resides client-side Implementation can best be realised client-side (e.g. harvesting desktop data with semiBlog ) Server-side metadata: Data to be used resides server-side Implementation can best be realised server-side (e.g. harvest WordPress database tables with WordPress SIOC plugin ) Client side versus server side

Semantic blogging references Bojars, Breslin and Möller, “Using Semantics to Enhance the Blogging Experience”, ESWC 2006 Cayzer, “Semantic Blogging: Spreading the Semantic Web Meme”, XML Europe 2004 Karger and Quan, “What Would It Mean to Blog on the Semantic Web?”, ISWC 2004 Ohmukai and Takeda, "Semblog: Personal Publishing Platform with RSS and FOAF”, FOAF Galway 2004

4. From Wikis to Semantic Wikis Semantic Web 2.0: Creating Social Semantic Information Spaces

A community-developed documentation project “ A piece of server software that allows users to freely create and edit Web page content using any Web browser. Wiki supports hyperlinks and has a simple text syntax for creating new pages and crosslinks between internal pages on the fly.” Wiki comes from the Hawaiian word for quick In brief: Interlinked websites Collaborative editing Simple syntax e.g. Wikipedia.org What are wikis? (1) JohnGrisham He is the author of PelicanBrief . He lives in Mississippi. He writes a book each year. He is published by RandomHouse .

What are wikis? (2) A wiki (or WikiWikiWeb) is free software that was created by several designers to create a website that anyone is allowed to access, add to and edit It relies on cooperation, checks and balances of its members, and a belief in sharing of ideas There are several forms of wikis such as TWiki and the WikiWikiWeb because the designers allowed wikis to be open, allowing others to even change the original format Wikis are being used in many ways, including Wikipedia.org, a highly used, online, free-access encyclopedia

Some uses of wikis Wikis are being used for: online encyclopaedias free dictionaries book repositories event organisation software development writing research papers project proposals

Entering information Anyone can edit an existing wiki article If an article does not exist on a particular topic, you can create it If someone messes up an article (deliberately or erroneously), there is a revision history so you can revert the contents

Problems with traditional wikis Structured access Information reuse JohnGrisham He is the author of PelicanBrief . He lives in Mississippi. He writes a book each year. He is published by RandomHouse . Structured access: Other books by JohnGrisham (navigation) All authors that live in Europe? (query) Information reuse: The authors from RandomHouse (views) And what if I don't speak English? (translation)

Personal wikis Enabling personal information management Should be very simple, very fast, very usable “ Note-taking on steroids” Examples include Tomboy, wikidPad, VoodooPad Notes, links, categories (to do lists, appointments) Popularity: simplicity, usability

What are semantic wikis? A wiki that has an underlying model of the knowledge described in its pages Semantic wikis allow to capture or identify further information about the pages (metadata) and their relations Knowledge model available in a formal language, so that machines can (at least partially) process and reason on it A semantic wiki would be able to capture that an "apple" article is a "fruit" (through an inheritance relationship) and present you with further fruits when you look at apple Some are used for personal knowledge management, others aimed at KM for communities http://wiki.ontoworld.org/wiki/Swikig http://www.semwiki.org/

From wikis to semantic wikis: the “sweet spot”

Semantic wiki prototypes At least 22 semantic wiki prototypes to date For a comprehensive list see: wiki.ontoworld.org/index.php/Semantic_Wiki_State_Of_The_Art or www.cfcl.com/rdm/MBD/mbd_sem_wiki.php Semantic wikis are aiming at collaboration Typically web based (two modes) Semantic personal wikis are aiming at personal information management Typically a desktop application (one mode)

Platypus semantic wiki A page per resource Current resource as object Current resource as subject Metadata is explicitly added separately from the text content (using N3 or RDF/XML)

SemperWiki semantic personal wiki Annotation primitives: Page: CamelCase, absolute: http://example.org, qname: dc:title Literal: “...” Annotation: predicate object Query: subject predicate object Advanced access: Intelligent navigation Query Data reuse: Structured information Views

Content and structural metadata in semantic wikis

Future work for (personal) semantic wikis Make them collaborative, through P2P or shared storage mechanisms: Desktop front-end Shared back-end Allow sophisticated annotations: Blank nodes Compound statements Integrate with the desktop: Drag and drop desktop items Annotate these items

Semantic wiki references Aumueller, “Semantic Authoring and Retrieval within a Wiki”, ESWC 2005 Oren, “SemperWiki: A Semantic Personal Wiki”, Semantic Desktop Workshop, ISWC 2005 Tazolli et al., “Towards a Semantic Wiki Wiki Web”, ISWC 2004 Poster Muljadi and Takeda, “ Semantic Wiki as an Integrated Content and Metadata Management System”, ISWC 2005 Völkel, “SemWiki - A RESTful Distributed Wiki Architecture”, Wiki Symposium 2005

5. Semantic Search Semantic Web 2.0: Creating Social Semantic Information Spaces

Towards a Semantic Web search engine Currently, Google searches mainly plain text Need integrated, conceptual query answering over various sources and kinds of data: semi-structured data (RDF, actual SW data) unstructured data (i.e. human language text) structured data (i.e. databases) Goal to provide answers instead of document lists (or both)

Querying semi-structured data Data and schema are represented in same data model RDF = graph topology + (string) literals Queries can be posed without or with only partial knowledge of schema Queries are precise with specified semantics (as long as you disallow keyword-based queries) High precision of results (1.0), but possibly low recall: Don’t get expected results if, for example, you query for foaf:Person with foaf:name “John Breslin” since “John G. Breslin” won’t match

Latent semantic indexing: Provides a means to measure distance between terms Statistical method Query reformulation: Methods to relax queries to get higher recall for “imprecise” keywords (homonyms, synonyms…) based on e.g. WordNet Query expansion for keyword-based searches

Searching over RDF RDF consists of the graph structure and literals Enable keyword search over content of string literals, and combine these with structured queries Various RDF data stores supporting various RDF query languages: Stores: Jena, Kowari, Redland, Sesame, YARS, etc. Query languages: N3QL, RDQL, RQL, SPARQL, Triple, etc.

Where do we get the semistructured data from? MySQL databases (via wrappers) GRDDL Microformats RDF files Crawl RDF files linked via rdfs:seeAlso Get HTML pages and apply GRDDL to parse out semistructured data Use GRDDL to parse microformat tags Crawling Semantic Web data

Semantic search references Anyanwu, Maduko and Sheth, “Semantic Querying: SemRank”, WWW2005 Harth, Kruk and Decker, “Graphical Representation of RDF Queries”, WWW2006 Poster Deerwester et al., “Latent Semantic Indexing”, JSIS 1990 Guha et al., “Semantic Search”, WWW2003 Harth and Decker, “Optimized Index Structures for Querying RDF from the Web”, LAWeb 2005 Ding, Finin et al., “Swoogle”, CIKM 2004

6. Semantics in Digital Libraries Semantic Web 2.0: Creating Social Semantic Information Spaces

Semantics in digital libraries Opportunities for applying semantics: Search User interface Metadata catalog Interface

Semantic digital library prototypes D-SPACE with Simile: Collaboration with MIT Libraries, CSAIL, W3C and HP Labs initially JeromeDL semantic digital library: Joint project between DERI Galway, DERI Innsbruck and the Polytechnic University of Gdansk BRICKS prototype: Integrated project funded by EU FP6 to create a digital library management system for cultural heritage

Simile set of tools How will scholars find relevant content on the Web? SIMILE tools: Longwell : Web-based faceted browser for RDF metadata Piggy Bank : Firefox extension for desktop metadata management (similar to EndNote) Solvent : Scripting language for HTML web page scraping into RDF Semantic Bank : Tool for “publishing” Piggy Bank collections to a group or to the world Welkin : RDF viewer, data exploration tool Gadget : Command line XML inspector (RDF conversion aid)

Step 1: Getting started (Scenario by Stephen J. Garland & Mick Bass) 3 OCW courses Let’s start by clicking here Facets for browsing 787 OCW resources 2384 ARTstor resources

Step 2: Exploring one collection Let’s click to focus on an early abstract artist 137 images on island

Step 3: Pausing to think Narrow focus raises questions: What else did Gorky do? Who was doing similar work? Let’s click to find out more about Gorky by removing a restriction

Step 4: Redirecting the search Two islands in view now, linked by Gorky bridge Let’s click to cross bridge

Step 5: Exploring a second collection

Semantic digital library technologies and research JeromeDL – e-library with semantics A digital library based on the Semantic Web Conforms to librarian standards (like MARC21) Semantic query expansion and ontology based navigation FOAFRealm – identity management Can define polices based on social networking information Access rights delegation, social semantic collaborative filtering MarcOnt – semantic bibliographic description initiative Bibliographic ontology compatible with MARC21, BibTeX, DC MarcOnt portal for collaborative ontology lifecycle management MarcOnt ontology mediation service HyperCuP - lightweight peer to peer implementation Efficient broadcast algorithm Domain-based overlay networks

Information management in JeromeDL

IR architecture in JeromeDL Fulltext Index FOAFRealm Repository Structure Repository MarcOnt Repository Resources’ Content (typed) keywords RDF Query OpenSearch RSS collaborative filtering local interface distributed interface types translation semantic query expansion RDF Repositories Secure Snapshot

What is social semantic collaborative filtering? Goal: To enhance individual bookmarks with shared knowledge within a community Users annotate catalogues of bookmarks with semantic information taken from DMOZ or WordNet vocabularies Catalogs can include (transclusion) friend's catalogues Access to catalogues can be restricted with social networking-based polices SSCF delivers: Community-oriented, semantically-rich taxonomies Information about a user's interest Flows of expertise from the domain expert

Example of social semantic collaborative filtering foaf:knows xfoaf:include xfoaf:bookmark

What is BRICKS? The BRICKS project is: “ Building Resources for Integrated Cultural Knowledge Services” An integrated project in the sixth EU framework programme Aiming at establishing the organisational and technological foundations of a distributed digital library system Also aiming to build an open scalable infrastructure Going to develop value-added application services Infrastructure requirements: Open and distributed (P2P) Component-based software architecture Expandability, scalability, availability, interoperability

BRICKS and Semantic Web technologies In BRICKS, metadata repositories are: Responsible for managing cultural assets Serving as access points for search and discovery services Integrating metadata from existing systems into a BRICKS metadata repository means dealing with: Heterogeneous metadata schemas Heterogeneous systems The BRICKS approach is to use: RDF for handling metadata internally OWL to model the semantics of metadata

Search and discovery in BRICKS BRICKS is providing three types of search mechanisms on the available (RDF) metadata: Simple (fulltext) search As used on Google Advanced search Field-value search with various operators and boolean combinations Ontology-based search Like advanced search, but with inference support Problem: Many institutions tend to provide metadata only in simple unqualified Dublin Core, so no use for ontology-based search Thesaurus-based search (fourth type for the future)

Semantic digital library references Kruk, Decker and Zieborak, “JeromeDL - Adding Semantic Web Technologies to Digital Libraries”, DEXA 2005 Kruk, Synak and Zimmermann, “MarcOnt - Integration Ontology for Bibliographic Description Formats”, DC 2005 Kruk and Decker, “Semantic Social Collaborative Filtering with FOAFRealm”, Semantic Desktop Workshop, ISWC 2005 Schlosser, Sintek, Decker and Nejdl, “Ontology-Based Search and Broadcast in HyperCuP”, ISWC 2002 Weinstein and Birmingham, “Creating Ontological Metadata for Digital Library Content and Services, IJDL 1998 Yee, Swearingen, Li and M. Hearst, “Faceted Metadata for Image Search and Browsing”, SIGCHI HFCS 2003 Longwell, http://simile.mit.edu/longwell/ Piggy Bank, http://simile.mit.edu/piggy-bank/ Semantic Bank, http://simile.mit.edu/bank/ BRICKS, http://www.brickscommunity.org/

7. Semantics in Community Portals Semantic Web 2.0: Creating Social Semantic Information Spaces

What are online communities? (1) People form online communities by combining one-to-one (e.g. e-mail and instant messaging), one-to-many (web pages and blogs) and many-to-many (forums, wikis) forms of communication And to recap from earlier… “ Social software enables people to rendezvous, connect or collaborate through computer-mediated communication and to form online communities .” - Wikipedia

What are online communities? (2) Pre-Web and Web 1.0: BBS services Mailing lists USENET Web-based bulletin boards Web 2.0: Multi-forum sites Online social networks Weblogs Wikis

Evolution of online community sites Online community sites: Provide a valuable source of information May contain rich meta-information But are isolated from one another: Many sites discussing complementary topics Next steps: Connect sites together Add more value: Let other sites know more about the structure and contents Make more use of tagging and semantic metadata

Existing connections using RSS, Atom syndication First step towards connecting online community sites: More visibility through aggregation and search Benefits: Good tool support Many consumers Shortcomings: Little information about structure of the site or community Feeds typically include only last five to 20 items How can we access information about the whole site?

What is SIOC? (2) Semantically-Interlinked Online Communities (SIOC) Connecting forums, posts from many types of online communities (blogs, forums, mailing lists, etc.) Interesting possibilities: Distributed linked conversations Decentralised discussion channels and communities “ I […] think the concept is HOT” – Robert Douglass, Drupal Developer http://rdfs.org/sioc/

Assigning topic metadata The sioc:topic (category) property is used to assign topics to SIOC primitives: Post, Forum, Site, etc. Can use existing category hierarchies: Upper level category systems: Open Directory Project, WordNet, OpenCYC Site specific category systems: Define community site’s existing category hierarchy in SKOS 1 Provide mapping to the upper level category system “ Weak” category systems are described using sioc:subject : Tags, keywords, folksonomies 1 SKOS – Simple Knowledge Organisation System - http://www.w3.org/2004/02/skos/

Create SIOC export modules for popular open-source discussion systems Initial versions of SIOC metadata exporters created for: Content management system (Drupal) http://rdfs.org/sioc/drupal Bulletin board system (phpBB) [in progress] Blogging system (WordPress) http://rdfs.org/sioc/wordpress French blogging system (DotClear) http://apassant.net/blog/2006/03/12/75-plugin-sioc-pour-dotclear Infecting the Web Infrastructure: During next upgrade cycle gigabytes of community data become available How can SIOC data be created?

Sample SIOC export from WordPress

Browsing SIOC (or other RDF) with Piggy Bank

Finding new interlinks with SIOC Use SIOC metadata to infer new connections between posts, users, forums and community sites Connections: Posts by the same user Posts on the same topic Posts by friends of a user (social network) Interests of users subscribed to a particular community forum . . . Re-use connections Store inferred connections using property sioc:related_to

SIOC for semantic forums There is already lots of RSS and Atom metadata being produced and consumed for blogs : Often more applicable to standalone sites, as the notion of “community” is not prominent: blogs are per-user and decentralised, with a sense of individual “ownership” But lots of relevant information is missing, e.g. metadata on the original poster, details of post replies and their contributors In forums , the missing metadata is very important : Who contributed to what parts of a community “ What topics have received the most replies from the greatest number of individuals?” Forums could also make use of functionality from the blogging community, e.g. trackbacks and tagging

Tagging forum content Tagging has only recently become a feature of forums, even though it should and could be used to interlink discussions on related topics: http://mods.invisionize.com/db/index.php/f/6314 http://www.phpbbhacks.com/download/6145 http://www.vbulletin.org/forum/showthread.php?t=111887 The next step is to produce SIOC exporters for popular bulletin board systems such as InvisionBoard, phpBB and vBulletin: In the presence of tags (e.g. from the modules above) or categorised content (e.g. from Drupal taxonomies), SIOC subject or topic metadata can be produced for cross-site linkage

BoardTracker, a “Technorati” for forums

Argumentative discussion topics similar to IBIS

Semantic forums and community portal references Breslin, Harth, Bojars and Decker, “Towards Semantically-Interlinked Online Communities”, ESWC 2005 Huynh, Mazzocchi and Karger, “Piggy Bank: Experience the Semantic Web Inside Your Web Browser”, ISWC 2005 Menendez, “Thread Description Language”, http://www.eyrie.org/~zednenem/2002/web-threads/ Reynolds, Shabajee and Cayzer, “Semantic Information Portals”, WWW2004 Poster Rittel and Knuz, “Issues as Elements of Information Systems”, UC Berkeley 1970

8. Realising the Memex and NLS: From the Desktop and Web to Social Semantic Information Spaces Semantic Web 2.0: Creating Social Semantic Information Spaces

Realising social semantic information spaces Web/Desktop : Help individuals in managing information on the Web/ their PC Semantic : Make content available to automated processing Social : Enable exchange across individual boundaries colleague friend acquaintance Social semantic peers peers Personal Semantic Web: a semantically enlarged intimate supplement to memory Social protocols and distributed search Email Person Topic Web s ite Document Image Event Person

Motivation for social semantic information spaces Current problems: Low level communication, everything is just e-mail... Insufficient collaboration infrastructure: High cost of setting up/maintaining Difficult to support ad-hoc collaboration

Reali sing social semantic information spaces: The f irst s ociety- s cale s emantic w eb a pplication Ontology-Driven Distributed Social Networking Ontology-Driven Social Networking Semantic Desktop Social Semantic Information Spaces P2P Networks Semantic Web Semantic P2P Social Networking Phase 1 Phase 2 Phase 3 Memex (Vannevar Bush) A memex is “a device in which an individual stores all his books, records, and communications.” Open Hypertext System (Doug Engelbart) “The open hyperdocument system (OHS) is a standards-based, open source framework for developing collaborative, knowledge management applications.” WWW (Tim Berners-Lee) “There was a second part of the dream […] we could then use computers to help us analyse it, make sense of what we re doing, where we individually fit in, and how we can better work together.” Today necessary technologies & communities exist: Standardised metadata: Semantic Web Scalable distributed infrastructure: P2P Computing Knowledge articulation and interaction: Desktop Technology Processing of unstructured and legacy information: NLP Human centric information exchange: Online Social Networks Driven by today's needs, in the spirit of seminal visions Challenge: Extension & merging of research streams NLP Desktop / Web Inspired by sociological perspectives: On group forming: Viral c ommunication (Reed) On innovative IT-based interaction and feedback: Social translucent systems (Erickson and Kellogg) Smart Mobs (Rheingold) On network modeling and algorithms: Social network research Small world properties Power law distribution (Barabasi and Huberman) Link-based authority algorithms, recommender algorithms (Perugini)

The desktop and the network become one Document exchange and collaboration Collaborative ontology and metadata creation/sharing Science peers application

Social semantic information space references Haystack, http://haystack.lcs.mit.edu/ Gnowsis, http://www.gnowsis.org/ Nepomuk, http://nepomuk.semanticdesktop.org Semantic Desktop, http://www.semanticdesktop.org

Conclusion Semantic (Web 2.0) => (Semantic Web) 2.0

Semantic Web 2.0: Creating Social Semantic Information Spaces

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