Web2.0 2012 - lesson 6 - web feed


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Lesson 6 course Web 2.0 2012
University of Camerino
RSS and WWeb feeds

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Web2.0 2012 - lesson 6 - web feed

  1. 1. Web 2.0 blog, wiki, tag, social network: what are they, how to use them and why they are important Feed, aggregation and tagging
  2. 2. This material is distributed under the Creative Commons "Attribution - NonCommercial - Share Alike - 3.0", available at http://creativecommons.org/licenses/by-nc-sa/3.0/ . Part of the slides is the result of a welcome distance collaboration with prof. Roberto Polillo, University Milan Bicocca ( http://www.rpolillo.it )
  3. 3. push vs. pull Push technologies : Es.: newsletter, mailinglist (subscribe / unsubscribe) Action taken by the server, which sends the messages to the recipients Pull technologies: Es.: Feed RSS, podcast, twitter, … Action taken by the client, which queries the server to see if there are new messages
  4. 4. pull benefits <ul><li>Can have a single &quot;aggregator&quot; for a variety of sources
  5. 5. Aggregator can filter messages from different sources, according to some criterion
  6. 6. No spam: the client must communicate its address
  7. 7. To stop the service the client should not communicate anything to the sources
  8. 8. The client is not &quot;disturbed&quot; to each new messages </li><ul><ul><li>-> order, security, efficiency </li></ul></ul></ul>
  9. 9. Web Feed Web feed: informational content, expressed in a stable form, interchangeable between applications Feeds are available from information sources (eg blogs, news sites, ...) and harvested by aggregators (or RSS readers) After the user subscription to a collection of feeds, the aggregator sends it to him on request http://en.wikipedia.org/wiki/Web_feed
  10. 10. RSS RSS (acronym for RDF Site Summary or for Really Simple Syndication) is based on XML, from which inherits simplicity, extensibility and flexibility. http://www.youtube.com/watch?v=0klgLsSxGsU (RSS) Almost alternative to traditional Web page RSS since 1999, Atom since 2004 Benefits compared to newsletter: <ul><li>a single aggregator for many sources
  11. 11. avoid spam
  12. 12. receive real-time information selected and customized </li></ul>Aggregators also for browsers: Firefox bookmarks Live, WizzRSS and other plugins https://addons.mozilla.org/en-US/firefox/search/?q=rss
  13. 13. Syndication In the language of the media, &quot;syndication&quot; is the process by which a single article is distributed simultaneously, through an intermediary, to many newspapers (eg Peanuts cartoons) <ul>R.Polillo - Ottobre 2010 </ul><ul>Agenzia </ul>
  14. 14. Aggregators: Netvibes Broadband network and billions of Web pages are valuable resources only if used carefully and intelligently. So we have to optimize time, streamlining navigation path and not get lost in the cognitive overload that often becomes chaos For example, Netvibes allows you to organize information sources into customized grids, now available on mobile The personalized page, easy to implement with simple drag and drop, let you keep an eye on the updates of sites of interest, mail, news, etc. We should not worry about going to look for information on the web but these are coming in automatically, to our aggregator http://www.netvibes.com/
  15. 15. Aggregators Google Reader: RSS and Atom feed aggregator, since 2005 To subscribe to a feed: URL of the feed (or the site that produces it) or search for feeds using keywords (or tags) Subscribing to RSS thematic groups of default (link &quot;Find and search feeds ...) Google Reader achieved a very cool feature, the plug-in Gears, which allowed you to read feeds offline (good also for Gmail etc.), now moving to HTML5 Access from mobile, including iPhone http://www.google.com/reader/view/#overview-page http://en.wikipedia.org/wiki/Google_Reader
  16. 16. Aggregators http://www.igoogle.com , started from 2005 Personal start page: web feeds, bookmarks, gadgets http://en.wikipedia.org/wiki/IGoogle http://news.google.com : news aggregator since 2002 Automatically aggregates information taken from over thousand of sources of information around the world by grouping items of similar content Available for different regions and languages News selected by computer algorithms, information sources are chosen by Google, the criteria are not known
  17. 17. Open data: feed and web services Now many data are stored in “repositories” and made available thruogh “web services” (see “Open data” above) Users can go and take the data exposed by a &quot;node&quot; on the Web as soon as they become available. This (another kind of pull) is a significant step forward in promoting access and sharing of data with respect to the push technology Data are no longer driven by the node that holds them to the central node, or parked in a common repository for subsequent statements, but are pulled away from the other nodes, alerted by a special web feeder (the irreplaceable RSS)
  18. 18. Tagging Tagging is the issuance of one or more keywords ( tags , in fact) to files on online platforms for sharing (documents, video, audio, etc) as YouTube videos or Flickr photos Tagging comes from different needs including the need to manage the huge amount of data online: in Web 1.0, and even more in 2.0, information overload (cognitive overload) is an important issue and a classification is necessary for retrieving relevant information.
  19. 19. Tagging The tagging can be seen as an evolution of classical taxonomy: from taxonomy to folksonomy where folksonomy is a neologism that means a more collaborative categorization using freely chosen keywords. It's a term which in effect belongs to the 2.0 world: in its definition, it refers to the methodology used by groups of people who work voluntarily to organize information into categories available through the web http://en.wikipedia.org/wiki/Folksonomy
  20. 20. Tag cloud The keyword cloud (tag cloud) provides a representation of common tags. The tag cloud is a visual representation of labels or keywords used on a website (or in a document) The list is typically presented in alphabetical order, with the characteristic of a larger font used for the most important words Example: http://www.flickr.com/photos/tags/ http://en.wikipedia.org/wiki/Tag_cloud http://tagcrowd.com/ http://www.wordle.net/
  21. 21. exercise 6 <ul><li>Get familiar with feed management in your browser
  22. 22. Analyze Google News
  23. 23. Define your own start page with one of the following applications: iGoogle, Netvibes, MyYahoo or another, exploring the collection of gadgets / widgets available
  24. 24. (comments and links on the wiki!) </li></ul>