PV005 Služby počítačových sítí Tomáš Obšívač | 2010 Semantic Web & Social Web Web pro lidi, web pro roboty Semantic Web & Social Web  Net and Web  We are here. :-)  Semantic Web  Web of data or Web with metadata  Social Web  How people change the Web & how the Web change people Net → Web → Graph Web | Semantic Web | Social Web  Net ~ propojené počítače III: International Information Infrastructure ↓  Web ~ prop. dokumenty = hypertext WWW: World Wide Web ↓  Graph ~ propojené „objekty“ GGG: Giant Global Graph O čem jsou všechny ty dokumenty?! http://dig.csail.mit.edu/breadcrumbs/node/215  Network effect ~ Metcalfe's law (1980)  The value of a network is proportional to the square of the number of connected nodes.  Proč se nám zdá, že svět je malý?  Small worlds – nejsme sousedé, ale jsme si blízko  Six degrees of separation (1967)  Shrinking world, časoprostorové rozpojení (A. Giddens), … Roots of Net's and Web's Success Web | Semantic Web | Social Web Web in numbers  Documents  Over 100 million websites, 30 bilion documents  2/3 indexed by search engines, 500x deep web (?!)  Is there any qualified judgement of amount of data?  More storage or data?  Average piece of information is never looked at by a human.  People  30% of world population online so far  CZ: 65%, US: 77% Web | Semantic Web | Social Web Semantic Web  Methods and technologies to allow machines to understand the meaning of information on the Web.  Questionable feasibility of W3C approach  Common framework that allows data to be shared and reused across applications.  Documents such as HTML page are readable by humans. Data are readable by machines.  Autonomous agents  smarter than common web browsers or thermostat ;-)  Metadata, relations Put machines to work Web | Semantic Web | Social Web  Best practices for publishing and connecting structured data on the Web:  URI, HTTP, RDF  Building blocks of the Semantic Web  5-star deployment scheme  http://lab.linkeddata.deri.ie/2010/star-scheme-by-example/ Linked Data ~ Web of Data (2006) Web | Semantic Web | Social Web  General method for conceptual description or modeling of information that is implemented in web resources, using a variety of syntax formats.  Similar to classic conceptual modeling approaches such as ERD or Class diagrams.  Labeled, directed multi-graph  Triple: subject-predicate-object expression  Example: Tomáš má e-mail obsivac@fi.muni.cz.  Subject: https://is.muni.cz/osoba/obsivac  Predicate: has the e-mail address  Object: mailto:obsivac@fi.muni.cz  Notations for RDF (e.g. RDF/XML, Notation3, RDFa) Resource Description Framework Web | Semantic Web | Social Web  RDF vocabulary  described by RDF Schema, OWL, …  Formal knowledge representation  Set of concepts (classes) within a domain and their properties (attributes) and relationships  Individuals  Allows reasoners to infer about domain's entities  Semantic Web application can exists w/o ontology. Ontology Web | Semantic Web | Social Web  Friend of a Friend  FooF describe persons, their activities and their relations to other people and objects.  DBpedia  One of Linked Data's datasets  A community effort to extract structured information from Wikipedia.  Which Skyscrapers in China have more than 50 floors and have been constructed before the year 2000? • http://dbpedia.neofonie.de/browse/ Examples Web | Semantic Web | Social Web  SPARQL  Example  spammer's dream :-) PREFIX foaf: SELECT ?name ?email WHERE { ?person a foaf:Person. ?person foaf:name ?name. ?person foaf:mbox ?email. } How to query RDF data? Web | Semantic Web | Social Web  Microformats.org  RDF in attributes  Příklad z Wikipedie:  Microdata (HTML5) Microformats, RDFa, Microdata Web | Semantic Web | Social Web  Augmented reality  Data about local reality, layers over maps  Google Rich Snippets (and local search)  Events, reviews, People, …  http://www.google.com/support/webmasters/bin/answer.py?answer=99170  Social Graph API demo Any use today? Web | Semantic Web | Social Web Social Web  Media  Channel or tool to deliver data.  One-to-one, one-to-many, many-to-many  User-generated content  e.g. player generated content (common in RPG)  Prosumer (A. Toffler, 1980, M. McLuhan 1972) Web as a kind of Social Media Web | Semantic Web | Social Web  People socialize and interact on the Web. How?  We form online communities. How?  Membership Lifecycle (Amy Jo Kim) • Lurker, Novice, Regular, Leader, Elder  90-9-1  Motivations for contributing • „revenge“, „ego boost“, belongingness and influence  Social networking service  Focused on people vs. hobby/interest  Reflects part of social graph How people change web? Web | Semantic Web | Social Web  Which attributes make software “social”?  Identity – who are you?  Reputation – what others think?  Presence – where are you?  Relationships – who/what are you connected with?  Groups – organization of connections  Conversations – discussions, topics  Sharing – content contribution  Yes and again, people make it. Social Software Web | Semantic Web | Social Web  Many possible measures and methods  Node centrality, topology, bridge, path lengths, reach, clustering  E.g. Collaboration graph  CG are used to measure the closeness of a network participants.  Social graph  Facebook attempt to rule the web. Social Network Analysis Web | Semantic Web | Social Web  Knowledge sharing  Crowdsourcing (J. Howe, Wired Mag, 2006)  Outsourcing tasks to community  The Wisdom of Crowds (J. Surowiecki, 2004)  Network society (M. Castells, since 1996)  Step further from information (aka postindustrial) society  Attention Economy, Economy of Free, Link Economy, Wikinomics  Wikinomics Forum 2010, sobota 4. 12., FF UK How web influence society? Web | Semantic Web | Social Web Missuse, Issues  Vandalism, spam, flames, phising, leaking, plagiarism, addiction, Continuous Partial Attention, procrastination, …  Privacy, stalking – First time in history, publicity is cheap and privacy is expensive.  Social exclusion (digital divide) Web | Semantic Web | Social Web  Orientovaný prakticky, rádoby pro pokročilé, max. 20 studentů ve skupině (x 3 skupiny)?  Zvaní přednášející – experti  Máme je natočené – video.muni.cz  Martin Hassman, Jan Sládek, Jirka Kosek, Martin Kopta, Jan Korbel, David Grudl, Veronika Rojkovičová, Radek Pavlíček, Emil Hampejz  Ukončení  Prezentace na domluvené téma, ~15 min.  Prezence max. 2 neomluvené  Projekt konkrétní řešení (může být týmové)  http://www.fi.muni.cz/~xobsivac/PV219/ Web | Semantic Web | Social Web PV219 Seminář webdesignu PV219: example webdev topics Web | Semantic Web | Social Web  Mobile web  More mobile browsers than desktop ones by 2013.  Responsive web design • CSS media queries: