Open Menu Close Menu

TrackBack: Where Blogs Learn Their Places

Blogging is becoming the source for millisecond currency on the Web. When the news that Google had decided to buy Pyra Labs, the company that pioneered some of the earliest blogging software, was announced, it was reported essentially live on the blog of Dan Gillmor who was sitting in the audience with his laptop connected to his blog site. Communication in Internet time keeps getting shorter.

Since then blogging has become a standard tool for faculty, students, and just about anyone who wishes to publish their thoughts worldwide. Interaction, the ability to comment on posts of others, was a feature of the earliest blogging tools. While commenting on the postings of others facilitates a certain amount of communication, the threshold to form communities is still far too high. The individual publishing paradigm of the blog has taken a turn toward community.


Eons ago in the blogsphere, let’s see, that would be about August of 2002, the good people at the company Movable Type released a new protocol. The protocol is based on REpresentational State Transfer, a phrase describing the essence of the Web’s architectural style (see RESTwiki/moin.cgi/RestArchitecturalStyle for more information). The idea of TrackBack is to “push” communication between posts made on different Weblogs. Here’s how it works.

Someone, let’s say Tom, has written a post on his own Weblog that comments on a post in another person’s Weblog, say Paula’s. How d'es Paula know or learn about Tom’s interest and reference to her post? Tom could have gone to Paula’s Weblog and posted a note there saying he liked Paula’s comment and wrote about it on his blog at However, this takes an extra degree of effort, and is just the sort of communication barrier that keeps like-minded people from forming communities. What is needed is a form of remote comment—rather than posting the comment directly on Paula’s Weblog, Tom posts his comment about what Paula has written on his own Weblog, then he sends a TrackBack ping to notify Paula.

A TrackBack ping is blogspeak for a short message sent from one Web server to another.

What d'es this accomplish? Paula can now list all the sites that have referenced her erudite prose on her Web site. This lets those browsing her Weblog read all the reactions to her posting from wherever they were written and posted around the Web. Among those listed, of course, would be Tom’s. Because this information is in machine-readable format (the ping message), software tools can read them and draw the Web of interaction around this particular posted topic automatically. The point of all this is to make explicit the connections between ideas (postings) and minimize the effort a browsing member of the blogging community has to expend—they don’t have to explicitly click on each referenced blog URL to read the set of related postings about Paula’s expository prose.

The TrackBack protocol is an open set of communication rules, thus letting vendors of many different blogging engines develop their piece of comparable functionality.

TrackBack, as a form of remote commenting, is just the tip of the iceberg.

Content Aggregation
The initial purpose of the TrackBack protocol was to provide a way of aggregating posts made by various bloggers about a particular topic. It addressed the problem that while a proliferation of blogs gives voice to many, it distributes the conversation such that it becomes next to impossible to follow the idea as expressed across these many blogs.

The approach taken was to suggest that someone might start a dedicated TrackBack blog on a particular topic. This special blog would not be used by the owner of the blog to wax p'etic on topics of his or her choice, but become a repository dedicated to a single topic. For example, imagine a site, which collects Weblog posts about the Civil War. Anyone interested in reading about the Civil War could look at this site to keep updated on what other Webloggers were saying about the Civil War, see photographs from that period in magazines, etc. This is accomplished when those who do write on their individual blogs about the civil war initiate a TrackBack ping to the designated collector site.

It’s pretty clear that discipline-based TrackBack blogs might turn out to be particularly interesting. What other ways might it valuable?

· If you’re running a conference or other event, a TrackBack blog about the conference might collect what people around the blogsphere are saying about it. (Sometimes anonymity can be good). There are some rather, ah, unique uses, as well.
· Post on a blog the current song playing on a different PC’s copy of WinAMP, the MP3 player (see
· Then again, there’s the implementation of TrackBack from WAP enabled mobile phones (see http://www.virtue It’s not clear that this one has much in the way of pedagogical value, but it’s interesting.
· A collection of your posts made on other blogs—the idea here is to have a blog that is a collection of all the postings you’ve made on other people’s blogs around the net (see

· Active updating of postings from a news database: memingo. This is a bit complicated, but it's an interesting idea. This site can be set up to read postings you've made to your blog. If it's not already in the database kept at memingo, it is added to it. If it is already there, and your blog has TrackBack enabled with auto-discovery, memingo can send a ping back to your blog with a pointer that g'es to the metadata about the article (see

The possibilities for TrackBack are only starting to be tapped. What’s clear is simple tools can make a large difference in crossing the barrier between splendid isolation and true conversation on the Web.

In an analysis of Usenet News only a small percentage of the users of Usenet actually post content into it. The rest simply take advantage, and yet by most measures, Usenet is very popular. The key is to achieve a threshold of perceived activity that makes the reader sense the site is worthwhile.

Tools like TrackBack extend the blogs by providing markers between sites that can facilitate the creation of community. Retaining community in the electronic fog is a pretty good goal.

Pyra Labs

Movable Type

Movable Type TrackBack for Beginners


What is TrackBack?

* Case Western Reserve University opened 1,230 wireless access points, providing free Internet access to faculty, students, staff and visitors. It is part of a OneCleveland plan to blanket the city with free wireless Internet access.

* A Chinese government-owned bookstore chain placed a order with a Canadian textbook publisher for a million dollars' worth of IT textbooks.

* posted its one-millionth college professor rating.

* A federal jury found Microsoft guilty of improperly using technology owned by the University of California in its Internet Explorer browser.

* AIU Online, a for-profit university, is offering secure electronic signature capabilities on all legal documents required for students.

For these and other news stories, or to subscribe to our eNewsletters, Syllabus News Update and Syllabus IT Trends,

comments powered by Disqus