3/12/2018 Semantic Web Services SS 2018 Web Science Anna Fensel 12.03.2018 © Copyright 2010 Dieter Fensel and Ioan Toma, updated by Anna Fensel in 2016‐2018 1 Where are we? # Title 1 Introduction 2 Web Science + Cathy O’Neil’s talk: “Weapons of Math Destruction” 3 Service Science 4 Web services 5 Web2.0 services 6 Semantic Web 7 Semantic Web Service Stack (WSMO, WSML, WSMX) 8 OWL-S and the others 9 Semantic Services as a Part of the Future Internet and Big Data Technology 10 Lightweight Annotations 11 Linked Services 12 Applications 13 Mobile Services 2 1 3/12/2018 Outline • Motivation • Web Science • Web Evolution – Web 1.0 – Traditional Web – Web 2.0 – Social Web • Major breakthroughs of Web 2.0 – Web 3.0 – Semantic Web • What Web Science could be – The computer science of the 21st century – Extension to Data Science • Summary • References 3 MOTIVATION 4 2 3/12/2018 Motivation The Web Today http://www.youtube.com/watch?v=6gmP4nk0EOE 5 Motivation “[…] As the Web has grown in complexity and the number and types of interactions that take place have ballooned, it remains the case that we know more about some complex natural phenomena (the obvious example is the human genome) than we do about this particular engineered one.” A Framework for Web Science T. Berners-Lee and W. Hall and J. A. Hendler and K. O'Hara and N. Shadbolt and D. J. Weitzner Foundations and Trends® in Web Science 1 (2006) A new science that studies the complex phenomena called Web is needed!! 6 3 3/12/2018 WEB SCIENCE 7 Web Science definition A new science that focuses on how huge decentralized Web systems work. “The Web isn’t about what you can do with computers. It’s people and, yes, they are connected by computers. But computer science, as the study of what happens in a computer, doesn’t tell you about what happens on the Web.” Tim Berners-Lee “A new field of science that involves a multi-disciplinary study and inquiry for the understanding of the Web and its relationships to us” Bebo White, SLAC, Stanford University Shift from how a single computer works to how huge decentralized Web systems work 8 4 3/12/2018 Endorsements for Web Science “Web science represents a pretty big next step in the evolution of information. This kind of research likely to have a lot of influence on the next generation of researchers, scientists and, most importantly, the next generation of entrepreneurs who will build new companies from this.” Eric E. Schmidt, CEO Google (2011-2015) “Web science research is a prerequisite to designing and building the kinds of complex, human-oriented systems that we are after in services science.” Irving Wladawsky-Berger, IBM 9 Web science – multi-disciplinary approach http://webscience.org/images/collide.jpg 10 5 3/12/2018 The Goals of Web Science • To understand what the Web is • To engineer the Web’s future and providing infrastructure • To ensure the Web’s social benefit 11 Scientific method • Natural Sciences such as physics, chemistry, etc. are analytic disciplines that aim to find laws that generate or explain observed phenomena • Computer Science on the other hand is synthetic. It is about creating formalisms and algorithms in order to support particular desired behaviour. • Web science scientific method has to be a combination of these two paradigms 12 6 3/12/2018 What Could Scientific Theories for the Web Look Like? • Some simple examples: – Every page on the Web can be reached by following less than 10 links – The average number of words per search query is greater than 3 – Web page download times follow a lognormal distribution function (Huberman) – The Web is a “scale-free” graph • Can these statements be easily validated? Are they good theories? What constitutes good theories about the Web? http://webcast.bibalex.org/Presentations/Bebo91108.ppt 13 Food For Thought Electricity : 1800 Electricity Now What are the analogies for Web Science and Design? Is our understanding of the Web like that of 1800 electricity? http://webcast.bibalex.org/Presentations/Bebo91108.ppt 14 7 3/12/2018 In the rest of this lecture • Web Evolution – Web 1.0 - Traditional Web – Web 2.0 – Social Web – Web 3.0 - Semantic Web • Future steps to realize Web science – Large scale reasoning – Rethinking Computer Science for the 21st century 15 WEB 1.0 – TRADITIONAL WEB 16 8 3/12/2018 Web 1.0 More than a 2 billion users more than 50 billion pages Static WWW URI, HTML, HTTP 17 Web 1.0 • The World Wide Web ("WWW" or simply the "Web") is a system of interlinked, hypertext documents that runs over the Internet. With a Web browser, a user views Web pages that may contain text, images, and other multimedia and navigates between them using hyperlinks. - wikipedia • The Web was created around 1990 by Tim Berners-Lee working at CERN in Geneva, Switzerland. 18 9 3/12/2018 Web 1.0 • A distributed document delivery system implemented using application-level protocols on the Internet • A tool for collaborative writing and community building • A framework of protocols that support e-commerce • A network of co-operating computers interoperating using HTTP and related protocols to form a ‘subnet’ of the Internet • A large, cyclical, directed graph made up of Web pages and links 19 WWW Components • Structural Components – Clients/browsers – to dominant implementations – Servers – run on sophisticated hardware – Caches – many interesting implementations – Internet – the global infrastructure which facilitates data transfer • Language and Protocol Components – Uniform Resource Identifiers (URIs) – Hyper Text Transfer Protocol (HTTP) – Hyper Text Markup Language (HTML) 20 10 3/12/2018 Uniform Resource Identifiers (URIs) • Uniform Resource Identifiers (URIs) are used to name/identify resources on the Web • URIs are pointers to resources to which request methods can be applied to generate potentially different responses • Resource can reside anywhere on the Internet • Most popular form of a URI is the Uniform Resource Locator (URL) 21 Hypertext Transfer Protocol (HTTP) • Protocol for client/server communication – The heart of the Web – Very simple request/response protocol • Client sends request message, server replies with response message – Provide a way to publish and retrieve HTML pages – Stateless – Relies on URI naming mechanism 22 11 3/12/2018 HTTP Request Messages • GET – retrieve document specified by URL • PUT – store specified document under given URL • HEAD – retrieve info. about document specified by URL • OPTIONS – retrieve information about available options • POST – give information (eg. annotation) to the server • DELETE – remove document specified by URL • TRACE – loopback request message • CONNECT – for use by caches 23 HTML • Hyper-Text Markup Language – A subset of Standardized General Markup Language (SGML) – Facilitates a hyper-media environment • Documents use elements to “mark up” or identify sections of text for different purposes or display characteristics • Mark up elements are not seen by the user when page is displayed • Documents are rendered by browsers 24 12 3/12/2018 HTML HTML markup consists of several types of entities, including: elements, attributes, data types and character references – DTD (Document Type Definition) • <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> – Element (such as document (<html>…</html>), head elements (<title>…</title>) – Attribute: <span id='anId' class='aClass' style='color:red;' title='HyperText Markup Language'>HTML</span> – Data type: CDATA, URIs, Dates, Link types, language code, color, text string, etc. – Character references: for referring to rarely used characters: • "水" (in hexadecimal) represents the Chinese character for water 25 WEB 2.0 26 13 3/12/2018 Web 2.0 “Web 2.0 is a notion for a row of interactive and collaborative systems of the internet“ http://widgets-gadgets.com/2006_10_01_archive.html 27 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.” 28 14 3/12/2018 Web 2.0 People, Services, Technologies 29 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 Web sites blogging dialogue publishing participation CMS wikis flexibility, freedom directories tagging community taxonomy folksonomy Consumers Prosumers 30 30 15 3/12/2018 What is the Web 2.0? - Examples •Gmail • Google Notebooks (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: 150 web-APIs 31 31 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) 32 32 32 16 3/12/2018 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) 33 33 Wikis: Design Principles • Open Should a page be found to be incomplete or poorly organized, any reader can edit it as they see fit.