Professor Human Computer Interaction at Vrije Universiteit Amsterdam / VU
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Lecture 3: Vocabularies & Data Formats on the Social Web (2014)
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This is the third lecture in the Social Web course (2014) at the VU University Amsterdam. Visit the website for more information: http://thesocialweb2014.wordpress.com/
Lecture 3: Vocabularies & Data Formats on the Social Web (2014)
1. Social Web
2014
Lecture III: What DATA looks like on the Social Web?
Lora Aroyo
The Network Institute
VU University Amsterdam
Social Web 2014, Lora Aroyo!
Monday, February 17, 14
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2. Questions on Assignment 1?
Provide analysis of privacy issues on the (Social) Web
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three articles <--> three mind maps <--> main Social Web privacy issues
write for people who didn’t attend the course (max 3 pages)
Provide analysis of current privacy-related public initiatives
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legal contexts for privacy and ownership
compare the intentions of both initiatives (advantages & disadvantages)
your own vision on how this impacts the future of the social web
your own advise to policy makers with regards to privacy on the web.
links to Net Neutrality
Link to Hands-on session:
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what would change if SOPA/PIPA, ACTA, CISPA were active – would you still have access to the information
you pulled in for the assignments
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illustrate your answer showing what changes could appear in the graph from exercise 4 (Hands-on session
2), explain why. (max 1 page)
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all visuals, e.g. screenshots, diagrams, in appendix, use template
Deadline: 21 February 23:59
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3. History of Blogs
• evolved from online diaries in 1980’s
• ‘weblog’ Jorn Barger (1997) & ‘BLOG’ Peter Merholz (1999)
• one of the first ways to contribute (unstructured usergenerated) content on the Web
• Justin Hall recognized as pioneer blogger (1994)
• Nature: political, technical, art, journalistic, cultural, personal
• Software: WordPress, Blogger, LifeJournal
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4. Types of Blogs
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single- or multi-authored
photo-blog,Video-blog, Audio-blog
life (b)log, now - microlifeblog (twitter)
lifecasting: in 2007 by Justin Kan: webcam on a cap
Gordon Bell MyLifeBits: Microsoft SenseCam
http://www.justin.tv/
http://research.microsoft.com/en-us/projects/mylifebits/
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5. Wikis
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Wiki in Hawaiian meaning fast/quick
"the simplest online database that could possibly work" (Ward Cunningham)1995
first wiki software: WikiWikiWeb (the QuickWeb)
first example for a large scale collaborative editing = software + process
commonly implemented software package is MediaWiki (known from Wikipedia)
pages structure & formatting: simplified markup language - wikitext, or HTMLtags,
WYSIWYG editing
http://c2.com/cgi/wiki?WikiWikiWeb
Social Web 2014, Lora Aroyo!
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http://www.flickr.com/photos/kables/1220574200/
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7. Exploiting the crowd
• in wiki applications crowd contributes with collective
intelligence (primarily textual)
• later also other media & recourses emerged, e.g.,
photo, video, music
• crowdsourcing
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8. Mechanical Turk
• 1760 Wolfgang von Kempelen: The Turk
• 2005 Amazon: Amazon Mechanical Turk
• marketplace for work; people perform tasks
computers are lousy at, e.g. identifying items in
a photo/video, writing product descriptions,
transcribing podcasts
• HITs = human intelligence tasks
• require little time & offer little compensation
• workers & requesters
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17. Was the $ million Netflix prize a
victory for crowdsourcing?
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18. Folksonomy
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On the social web the user-generated content is organized in
light-weight ontologies, i.e., folksonomies
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Community-based semantics = a relationship between Users,Tags
& Resources
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user-created, bottom-up classification/categorization of
(domain) terms / user-labels, e.g., tags
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tagging = the social process where lay users attach labels to
resources (as opposed to annotation by professional experts)
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19. Folksonomy
•
On the social web the user-generated content is organized in
light-weight ontologies, i.e., folksonomies
•
Community-based semantics = a relationship between Users,Tags
& Resources
•
user-created, bottom-up classification/categorization of
(domain) terms / user-labels, e.g., tags
•
tagging = the social process where lay users attach labels to
resources (as opposed to annotation by professional experts)
Social Web 2014, Lora Aroyo!
Monday, February 17, 14
13
20. Folksonomy
•
On the social web the user-generated content is organized in
light-weight ontologies, i.e., folksonomies
•
Community-based semantics = a relationship between Users,Tags
& Resources
•
user-created, bottom-up classification/categorization of
(domain) terms / user-labels, e.g., tags
•
tagging = the social process where lay users attach labels to
resources (as opposed to annotation by professional experts)
Social Web 2014, Lora Aroyo!
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26. • cleaning messy data
• transforming data from one format to another
• fetching missing data
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27. • cleaning messy data
• transforming data from one format to another
• fetching missing data
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28. Structure on the Web
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In the evolution of the Web, Semantic Web refers to an approach
to add ‘semantics’ to the web, by naming terms in a domain
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A specification of such terms is called an ‘ontology’
For software: ontologies help to effectively use content on the
Web (like DB schemas)
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29. Vocabularies on the
(Social) Web
• to create interfaces or exchange data between applications
the software needs to know the terms in the data
• vocabularies define set of terms in a certain domain, e.g.,
describing people, relationships, content of different type
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31. Linked Data & FOAF
FOAF
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FOAF = Friend of a Friend, http://www.foafproject.org/,
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a machine-readable ontology describing persons, their
activities & their relations to other people and objects
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an open, decentralized technology for connecting
social Web sites, & the people they describe
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• model for publishing simple factual data
via a networked of linked RDF
documents
• FOAF is an attempt to use the Web to:
• integrate factual information with
information in human-oriented
documents (e.g. videos, books,
spreadsheets, 3d models)
• and info that is still in people's
heads
• linking networks of information with
Since mid-2000
networks of people
Stable core of classes & properties
New terms may be added at any time
FOAF RDF namespace URI is fixed
http://xmlns.com/foaf/spec/
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32. FOAF Files
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Documents, that adopt the conventions of RDF and may be written in XML,
RDFa or N3
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Contain FOAF vocabulary and other RDF vocabularies
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FOAF defines classes, e.g. foaf:Person, foaf:Document, foaf:Image
FOAF defines properties of those things, e.g. foaf:name, foaf:homepage
FOAF defines relationship that hold between members of these
categories, e.g. foaf:depiction relates something (e.g. a foaf:Person) to a
foaf:Image
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33. FOAF Example
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there is a foaf:Person
with a foaf:name property of 'Dan Brickley'
in foaf:homepage and foaf:openid relationships to a thing called http://danbri.org/
in foaf:img relationship to a thing referenced by a relative URI of /images/me.jpg
Create your own FOAF file: http://www.ldodds.com/foaf/foaf-a-matic
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41. FOAF Auto-Discovery
• If you publish a FOAF self-description (e.g. using
foaf-a-matic) you can make it easier for tools to
find your FOAF by putting markup in the head of
your HTML homepage
• Common filename foaf.rdf is a common choice
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42. SIOC
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Semantically-Interlinked Online Communities
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ontology for representing rich data from Social Web in RDF
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a standard way for expressing user-generated content
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methods for interconnecting discussions, e.g., blogs, forums & mailing lists; and
enable the integration of online community information
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used in conjunction with FOAF vocabulary for expressing personal profile &
social networking information
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http://sioc-project.org/
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44. <sioc:Post rdf:about="http://jbreslin.com/blog/2006/09/07/creating-connections">
1
<dc:title>Creating connections between discussion clouds with SIOC</dc:title>
2 <dcterms:created>2006-09-07T09:33:30Z</dcterms:created>
<sioc:has_container rdf:resource="http://jbreslin.com/blog/index.php?sioc_type=site#weblog"/>
<sioc:has_creator>
<sioc:UserAccount rdf:about="http://jbreslin.com/blog/author/cloud/" rdfs:label="Cloud"> 3
<rdfs:seeAlso rdf:resource="http://jbreslin.com/blog/index.php?sioc_type=user&sioc_id=1"/>
6
</sioc:UserAccount>
</sioc:has_creator>
<foaf:maker rdf:resource="http://jbreslin.com/blog/author/cloud/#foaf"/>
<sioc:content>SIOC provides a unified vocabulary for content and interaction description: a semantic la
that can co-exist with existing discussion platforms. 5
</sioc:content>
4 <sioc:topic rdfs:label="Semantic Web" rdf:resource="http://jbreslin.com/blog/category/semantic-web/"/>
<sioc:topic rdfs:label="Blogs" rdf:resource="http://jbreslin.com/blog/category/blogs/"/>
7 <sioc:has_reply>
<sioc:Post rdf:about="http://jbreslin.com/blog/2006/09/07/creating-connections/#comment-123928">
<rdfs:seeAlso rdf:resource="http://johnbreslin.com/blog/index.php?
8
sioc_type=comment&sioc_id=123928"/>
</sioc:Post>
</sioc:has_reply>
</sioc:Post>
• A post (1) titled "Creating connections between discussion clouds with SIOC" (2) created at
09:33:30 on 2006-09-07 (3) written by user "Cloud" (4) on topics "Blogs" and "Semantic
Web" (5) with contents described in sioc:content.
• (6) More information about its author at http://johnbreslin.com/blog/index.php?
sioc_type=user&sioc_id=1
• The post has (7) a reply and (8) detailed SIOC information about this reply can be found at
http://johnbreslin.com/blog/index.php?
sioc_type=comment&sioc_id=123928
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46. Activity Streams
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A list of recent activities performed by someone on a website
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Example: Facebook News Feed
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Activity Streams project aims at an activity stream protocol to
syndicate activities across social Web applications
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Major websites with activity stream implementations have
already opened up their activity streams to developers to use, e.g.,
Facebook and MySpace
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http://activitystrea.ms/
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47. Activity Streams
Specification
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an actor, a verb, an object and a target
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person performing an action on/with an object
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Geraldine posted a photo to her album
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John shared a video
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activity metadata to present to a user in a rich human-friendly
format, e.g. constructing readable sentences about the activity that
occurred, visual representations of the activity, or combining similar
activities for display
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Activities are serialized using the JSON format
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There is also an ATOM-oriented specification
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51. XFN
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Xhtml Friends Network
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defining a small set of values that describe personal relationships
In HTML and XHTML, these are given as values for rel attribute on a hyperlink. XFN
allows authors to indicate which weblogs belong to friends, whom they've physically met,
and other personal relationships. XFN values allow to humanize blogrolls and link pages.
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using XFN can easily style all links of a particular type, e.g, friends could be
boldfaced, co-workers italicized, etc.
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http://gmpg.org/xfn/
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52. XFN Example
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Joe has a set of five links in his blogroll: his girlfriend Jane; his
friends Dave and Darryl; industry expert James, who Joe briefly
met once at a conference; and MetaFilter.
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MetaFilter gets no value since it is not an actual person
Social Web 2014, Lora Aroyo!
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http://gmpg.org/xfn/intro
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53. 5 people who’ve met
friends vs. acquaintances
love vs. family
colleagues vs. co-workers
http://gmpg.org/xfn/intro
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54. Open Graph
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protocol originally developed in Facebook, “Like” button
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enables web pages to become a rich object in a social graph, i.e. any web
page to have the same functionality as any other object on Facebook
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prefix="og: http://ogp.me/ns#" specifies the OGP vocabulary
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55. OGP Explained
1. import the Dublin Core & Open Graph
Protocol vocabularies using the prefix
attribute
2. associate a prefix, dc and og with the
URL for each vocabulary
3. use dc:creator and og:title, which
are short-hand for the full vocabulary term
URLs http://purl.org/dc/
creator/creator and http://
ogp.me/ns#title, respectively
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57. RDFa
http://rdfa.info/play/
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another syntax for RDF
HTML5 extension for People, Places, Events, Recipes, Reviews markup
specify that a text is the name of a product, or person, or event = “adding semantic markup”.
RDFa 1.1 = specified for XHTML and HTML5 (for any XML-based language, e.g., SVG)
RDFa Lite = “a small subset of RDFa consisting of a few attributes that may be applied to most
simple to moderate structured data markup tasks.”
Publish your data as Linked Data through RDFa --> link to other URIs (others can link to your
HTML+RDFa)
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58. Microformats
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simple, open data formats built upon existing widely adopted standards
Designed for humans first & machines second
Highly correlated with semantic XHTML (aka the real world semantics,
lowercase semantic web, lossless XHTML)
“An evolutionary revolution”, by ryan king
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59. Your first microformat
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1.
2.
You can put a microformat on your website in less than 5 mins
Example: putting an hCard (online business card) on your site
Find your name somewhere on your website
Wrap your name in an fn (formatted name)
<span class="fn">Jamie Jones</span>
3.
Wrap it all in a vcard (declares that everything inside is the hCard microformat):
<span class="vcard"><span class="fn">Jamie Jones</span></span>
<address class="vcard"><span class="fn">Jamie Jones</span></address>
The address element indicates that the person in the hCard is the contact for the page
<p class="vcard">My name is <span class="fn">Jamie Jones</span> I dig
microformats!</p>
http://microformats.org/get-started
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60. Further microformats
• Add more information to your hCard
• Link to your friends and contacts with XFN
• Add events to your site with hCalendar
• Review movies, books, and more with hReview
http://microformats.org/get-started
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61. HTML Microdata
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allows machine-readable data to be embedded in HTML documents in an easyto-write manner, with an unambiguous parsing model
compatible with numerous data formats, including RDF and JSON
consists of a group of name-value pairs.
the groups are called items, and each name-value pair is a property
• itemscope is used to create an item
• itemprop is used to add a property to an item
Microdata DOM API
http://www.w3.org/TR/microdata/
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63. schema.org
• Google,Yahoo!, Bing
• a common vocabulary for
structured data markup on web
pages
• improve how sites appear in major
search engines
• Google rich snippets of reviews,
people, recipes, events in 2005
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64. Knowledge
Graph
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graph that understands real-world
entities and their relationships to one
another: things, not strings
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more than 500 million things
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results in 2013
tuned based on what people search for
more than 3.5 billion facts about and
relationships between these different
things
http://www.google.com/insidesearch/
features/search/knowledge.html
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71. Question?
For which things on the social web would more
vocabularies for embedded semantics be needed
(besides what we have already seen)?
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72. Hands-on Teaser
• mining data in various social web formats
• see the differences in what each of the formats can
contain & what purpose they serve
• start: simple search where we pull in some XFN data and
visualise a graph of people that we find on a website
• check: software you will be working with on the website
image
Social Web 2014, Lora Aroyo! source: http://www.flickr.com/photos/bionicteaching/1375254387/
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