Adam Weinroth asked Clay and I five questions about tagging in an email interview posted here.

As for uniform tagging, that can only work in situations where there is enough force to expend making the users behave uniformly, and where it is worth expending that force. For example, the Diagnostic and Statistical Manual, (DSM-IV) used by American psychiatrists and psychologists, provides a relatively standard way to diagnose mental disorders. It only works as well as it does, however, and that not perfectly, because it is produced by the American Psychiatric Association, which body can exert considerable force over its members, and DSM-IV is only to be used by the members.

The amount of human cost, in other words, in creating an enforcing uniformity is so high that attempts at such uniformity will fail in most cases. Fortunately, tagging allows for degenerate cases such as alternate spellings and phrasing. This would be a problem if there were only one tagger, responsible for a large group of users, but with every user a tagger, the loss stemming from degenerate cases quickly shrinks, while the value from multiple points of view grows.

Jon Udell has an interesting piece on (among other things) the use of del.icio.us tagging by InfoWorld editors as a way for them to work with each other and also interact with their readers.

We’re finding similar things at Nature. First, our social bookmarking service for scientists, Connotea, is proving useful as a collaborative tool for our journalists and editors. For example, editorial teams can use tagged links to communicate ideas and leads among themselves. Also, journalists researching particular stories can use the system to store and retrieve informative links under suitable tag names — and can choose to keep those links private, at least temporarily, if they’re worried about being scooped.

Second, Connotea enables greater interaction with readers. For example, collections of links gathered by a writer during their research can be released on publication of their article in order to provide readers with further sources of information. A recent example of this was Declan Butler’s Nature article on the new generation of laboratory information systems, which pointed interested readers to his accompanying collection of links.

As Jon Udell points out, such collections are future-proof because they can grow even after the URL has been distributed. This means that sometimes, as with Declan’s own collection of avian flu links, they can become important community resources that continue to be tracked by significant numbers of interested readers, potentially even long after the original article has become obsolete. Of course, readers can themselves contribute simply by using the same tag names. For example, the Connotea collections on bioinformatics and open access have attracted groups of users that turn these pages into something like pared-down group blogs.

With participative (or grassroots or citizen) journalism becoming an increasingly important theme inside media organisations and beyond, it’s intriguing to see that tagging also seems to have a role to play in facilitating exchanges between writers and their readers, and in blurring the boundaries between those traditionally distinct roles.

At Many2Many, Ross Mayfield writes about tag spam at Yahoo, referring to a post by Steve Rubel. I looked but couldn’t find anything I would call spam on the list of tags for Everyone’s Pages at Yahoo, then noted a comment on Rubel’s blog from Jeremy Zawodny: “you seem a bit too willing to yell spam in a crowded tag map.” Rubel responds to Zawodny (and others with similar comments) that he sees their point, and notes that “heard from the person who posted all of these links that he is tinkering with MyWeb2.0 and by accident imported all his browser bookmarks into the larger community.” He goes on to say that this still exposes “a big hole in all of these tagging sites.” He goes on…

Chung-Man Tam at Yahoo responded to Rubel: “It looks like one of our users is really just tagging stuff the way they want, enthusiastically I might add. I might not understand that tag (nor even like it), but if they find it useful I say go ahead and tag away.”

Why can I say that? Well remember folks, My Web 2.0 is a social search engine where your community shares their insights with you. While the web can sometimes seem like the Wild Wild West, the trusted web is a place where you decide who you want to listen to. If I like the stuff that someone saves and the tags that they’re using, I’ll connect to them! If I don’t…well, you know.

Interesting point in all this about social tagging: people have different ideas about what’s signal and what’s noise, and when we start sharing our categories (and patterns of thinking, insofar as those are represented by our categorization schemes), we see… differences! As in vive la.

I’m still not sure most of us would agree that the amount of thought and time put into tagging systems and tagging resources is worth the while.

I talked about some issues related to making and using tags at this year’s South by SouthWest Interactive Conference (SXSWi). Let me start out with some of those ideas here and add a few new ones just to set framework for our conversation:

Tags are good because:

• They show a user’s view of the data
• When in a hypertext system, they provide easy ways to sort and browse data
• They help with search because they may offer additional keywords for a resource that aren’t in the original resource
• Experts are not good at describing every possible keyword or concept that may apply
• Tags are additional (meta)data that can be analyzed by information retrieval systems

Tags are bad because:

• Experts may be a little better at describing resources (assuming that experts are the one posting and creating the resources in question)
• Tags may be too focused on one community of users for wide utility
• Once tagged, a dynamic resource may change, but the tags may not necessarily be updated to reflect this change
• Tags are just another system of resource identification to spam, spoof and game (especially tags as links to Web pages)

Do you agree? Disagree? What did I leave out?

Hi, I’m Don Turnbull – an Assistant Professor in the School of Information at the University of Texas at Austin. I teach more than a couple of courses related to issues that could revolve around tagging, including a course on what I call Knowledge Management Systems as well as Web Information Retrieval, Evaluation & Design and even about designing information systems from the perspective of Information Architecture & Design.

I’ve also been doing this kind of work in industry, including leading the research efforts at a startup that was acquired by Google. I currently also spend a bit of time consulting with software companies to develop new kinds of information systems as well as with other businesses to collect, manage and retrieve their own information.

I’m interested in tagging and ad-hoc taxonomies for a number of reasons. Primarily, because they seem to be leveraging the power of large numbers in concert with the practical intelligence of normal people, not just automated systems. The advent of user-defined taxonomies or even user-driven world views (let’s call them ontologies for this post), is transforming how we as individuals manage our own information, how we share it with others (like minded or not) and how we can both browse and search through personal and networked resources in a world where tags might just offer the silver bullet of metadata that helps us manage information overload.

I’ll do my best to talk about issues related to all these claims and ideas both here and on my own blog: donturn.com.

I just noticed – and perhaps I’m behind the times – that Amazon has supplemented its SIPs (statistically improbable phrases) with CAPs (capitalized phrases). For example, look at the “Inside This Book” subsection about halfway down this page. Amazon explains them this way:

Capitalized Phrases, or “CAPs”, are people, places, events, or important topics mentioned frequently in a book.

As with SIPs, if you click on one, you see all other works that also contain those capitalized phrases. Another cool idea from Amazon. (Wonder how it works in German, though.)