Tagging

Draft

Definition

Tags are labels for something. There are different classification systems, e.g. taxonomies like the ones used by librarians or folksonomies.

In the context of Web 2.0, Tagging means sticking keywords to something (a resource link, a web page, a picture, ...). The agents who can create tags are professionals, authors and users. One object can be tagged with as many words as one desires because there are no restrictions.

Other usages of tag: A label in syntax used in markup languages like XML to delimit an element.

Folksonomies

Thomas Vander Wal invented in 2004 the expression folksonomies. They are "naturally grown" collections of tags, i.e. implicit taxonomies that are constituted by people creating and using tags.

“In contrast to professionally developed taxonomies with controlled vocabularies, folksonomies are unsystematic and, from an information scientist's point of view, unsophisticated; however, for Internet users, they dramatically lower content categorization costs because there is no complicated, hierarchically organized nomenclature to learn. One simply creates and applies tags on the fly.” (Wikipedia:Folksonomy, 18:45, 14 September 2006 (MEST))

Since Folksonomies are open-ended by definition, they do have some advantages.

• They can quickly respond to innovations, new interests, new ways of looking at things etc. and, concerning the language, they reflect changing terminologies because they don’t have to respect a controlled vocabulary.
• “Perhaps the greatest benefit of folksonomy is its relevance in the information retrieval sense of the term -- that is, the capacity of its tags to describe the "aboutness" of an Internet resource. After all, folksonomies are generated by people who have spent a great deal of time interacting with the content they tag.” (Wikipedia:Folksonomy, 18:45, 14 September 2006 (MEST))
• A more intriguing argument is that they convey information at multiple layers, i.e. they are simultaneously systematic (will cover all sorts of interest of a given population), and personal and social (they also provide information about this population.

Of course there are also disadvantages to folksonomies:

• They are polysemic (one word has several meanings, this is why we use sometimes disambiguation pages in this wiki).
• For a same concept synonyms and various spellings may be used etc.
• They can include all sorts of meta noise (e.g. wrong tags or badly spelled tags).

There are solutions to avoid some "noise", i.e. propose a large, but fixed set of keywords to the users. Lars Pind(2005) proposes some ideas to make folksonomies work better:

• The suggestion of existing tags could help people in familiarizing whith the world of tags, avoiding inconstancies, obvious tags or general “noises”.
• The show of related tags and synonyms.
• The use of a layout devise to show the most used tags (e.g. size, colour).
• Once given a fixed problem domain, offer the users a list of tags from which they have to choose.

Collaborative tagging

“Collaborative tagging describes the process by which many users add metadata in the form of keywords to shared content.” (Golder & Huberman, 2006).

(Collaborative) Tagging is used in many social software applications. Most of these are folksonomies.

E.g.

• to manage one's own digital artifacts and links
• to allow people to share links (social bookmarking) and artifacts.
• to link people with same interests (“Tagging will help social groups form around shared semantics, in addition to shared semantics arising from, and helping to define, groups” Weinberger, 2005, retrieved April 20, 2007 )
• to calulate recommendations for a product (e.g. like Amazon does with keywords describing books)

Why does it work ?

Firstly, it's easy for users and requires only two steps of cognitive processing (Sinha, 2005). In contrast, filling in metadata forms is time-consuming, boring and difficult.

Second, metadata are ridid and don't work in the real world. An object is not always either of type 1 or type 2, but can be both or in between.

Metrics and visualization techniques can put some "order" into a big "tag soup", e.g. show which tags are close (e.g. see tag clouds) and therefore create "natural taxonomies".

“Tagging repudiates one of the deepest projects our culture has undertaken over and over again: The rendering of all knowledge into a single, universal framework. The semi-chaotic state of the “tagosphere” represents the nature of our shared world better than the cool marble columns of the old mono-order ever could” (Weinberger, 2005, retrieved April 20, 2007).

Discussion

Metadata taxonomies vs. folksonomies

• Some people hate metadata (DSchneider does because it's too much work)
• Some people hate tagging (DSchneider does because within large crowds some people may unintentionnally or intentionnally use wrong tags, and because it'is also means extra work.

 :)

See also the way MediaWikis use categories which is a sort of bookmarking. Each author can assign a category to a page. If it doesn't exist, the wiki engine creates a "wanted Category" page that needs to be edited in order to display the automatically generated list of pages. Categories can also be inserted into Categories (which turns it into a subcategory of the give category). Note: Categories in this wiki were made by a single user DSchneider. It's something in between a little folksonomy and reflection about our field.

Links

• Rashmi Sinha's blog entries on tagging

• Thinking about tagging and Web 2.0

Examples

• Mike Malloch's del.icio.us tags on social bookmarking (very useful)

References

• Farrell, Stephen and Tessa Lau, Fringe Contacts: People-Tagging for the Enterprise, WWW '2006 paper, PDF

• Golder, Scott and Bernardo A. Huberman (2006). "Usage Patterns of Collaborative Tagging Systems." Journal of Information Science, 32(2). 198-208. Abstract/PDF.

• Sinha, Rashmi, (2005). A cognitive analysis of tagging, (or how the lower cognitive cost of tagging makes it popular), HTML

• Vuorikari, Riina (2005), Social networking software and e-portfolios foster digitallearning networks, Special Insight Reports, European Schoolnet. HTML

• Vuorikari, Riina (2005), Innovation Brief: Can personal digital knowledge artefact's managment and social networks enhance learning ? PDF