Trackbacks and Pingbacks

Trackbacks were originally developed by SixApart, creators of the MovableType blog package. It’s a notification method between websites working as follows :

  • Person A writes something on their blog.
  • Person B wants to comment on Person A’s blog, but wants her own readers to see what she had to say, and be able to comment on her own blog
  • Person B posts on her own blog and sends a trackback to Person A’s blog
  • Person A’s blog receives the trackback, and displays it as a comment to the original post. This comment contains a link to Person B’s post

Most trackbacks send to Person A only a small portion (a teaser called an “excerpt”) of what Person B had to say. One problem is that there is no actual verification performed on the incoming trackback, and indeed they can even be faked.

Pingbacks were designed to solve some of the problems of trackbacks. The official pingback documentation is available on the website

The best way to think about pingbacks is as remote comments:

  • Person A posts something on his blog.
  • Person B posts on her own blog, linking to Person A’s post. This automatically sends a pingback to Person A when both have pingback enabled blogs.
  • Person A’s blog receives the pingback, then automatically goes to Person B’s post to confirm that the pingback did, in fact, originate there.

There are two significant differences between pingbacks and trackbacks : pingbacks and trackbacks use drastically different communication technologies (XML-RPC and HTTP POST, respectively) and pingbacks do not send any content.

A useful guide “Introduction to Blogging” with more details about trackbacks and pingbacks is published by WordPress.

World Wide Web, World Live Web, World Life Web

In 1994, in the wake of Tim Berners Lee‘s work, the World Wide Web was officially born. A global web, wide in its dimensions as in its contents. Over the years, these contents have literally exploded, imposing the use of search engines to try and sort out this fertile chaos on the basis of the principle of a classification ‘by relevance’. The domain name (DNS) to identify and classify web sites and to adress documents and the  “http protocol” (hypertext transfer protocol) to retrieve them are the main features of this first documentary age of the web.

Then came the World Live Web, an instantaneous subset of the World Wide Web, a web giving the latest published information in real time. Google News service was one of the pioneers of this second documentary age, but it also enables to refer to what is called micro contents (citizen media), e.g. comments on blogs. Specialised search engines like Technorati are integrated with tools that power the blogosphere and are able to index new content within ten minutes. According to Technorati data, there are over 175,000 new blogs every day. In april 2008, Technorati is tracking more than 100 million blogs and over 250 million pieces of tagged social media. For instance searching for in Technorati gives more than 100 results.

We are now entering a third documentary age, the World Life Web, in particular with the extraordinary boom of social networks (Facebook, MySpace) and of virtual worlds  (Second Life). The main issues of this new age are the sociability and the indexable and remixable nature of our digital identity as well as its traces on the network.

Olivier Ertzscheid, enseignant-chercheur (Maître de Conférences) en Sciences de l’information et de la communication au département Infocom de l’IUT de la Roche sur Yon (Université de Nantes) a publié un petit texte à vocation pédagogique sur ce sujet sur son blog personnel

Blogs, Blogrolls, Blogosphere, RSS newsfeeds, Permalinks

A weblog, or “blog”, is a personal journal on the Web that is updated frequently, most often displaying its material in journal-like chronological dated entries or posts.  Weblogs cover as many different topics, and express as many opinions, as there are people writing them. Weblogs are different from traditional media. Bloggers (someone who writes a blog ) tend to be more opinionated, niche-focused, and partisan than journalists, who strive for editorial objectivity. Many weblogs allow readers to write a reaction (comment) to what was written in the blog entry. A blogroll is a list of blogs and bloggers that any particular blog author finds influential or interesting. The online community of bloggers, their writings and the comments is called Blogosphere.

Weblogs usually offer RSS feeds (a file format that allows anyone with a website to easily “syndicate” their content)  to make part of their content (excerpts and links back to the originating website) available to other sites to use and publish the informations. Excerpts are optional hand-crafted summaries of the content. To provide an easy way to capture specific references to posts or articles in a blog, permalinks (a permanent identifier to a specific weblog post or article) are the preferred solution. Inbound links refer to hyperlinks from other sources citing that weblog. Outbound links refer to hyperlinks from the weblog to outside sources. The leading monitor of the world of weblogs is Technorati, a real-time search engine that is the largest source of fresh information about the global and local conversations going on all across the Web.