Tag cloud

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A tag cloud with terms related to Web 2.0
A tag cloud with terms related to Web 2.0

A tag cloud (or weighted list in visual design) is a visual depiction of user-generated tags used typically to describe the content of web sites. Tags are usually single words and are typically listed alphabetically, and the importance of a tag is shown with font size or color. [1] Thus both finding a tag by alphabet and by popularity is possible. The tags are usually hyperlinks that lead to a collection of items that are associated with a tag.

Contents

[edit] Definition

A tag cloud is a set of related tags with corresponding weights. Typical tag clouds have between 30 and 150 tags. The weights are represented using font sizes or other visual clues. Meanwhile, histograms or pie charts are most commonly used to represent approximately a dozen different weights. Hence, tag clouds can represent many more weights, though less accurately so. Also, frequently, tag clouds are interactive: tags are hyperlinks typically allowing the user to drill down on the data.

[edit] History

The first use of tag clouds on a high-profile website was on the photo sharing site Flickr, created by Flickr co-founder and interaction designer Stewart Butterfield.[2] That implementation was based[citation needed] on Jim Flanagan's Search Referral Zeitgeist,[3] a visualization of Web site referrers. Tag clouds have also been popularized by Del.icio.us and Technorati, among others.

The first published appearance of a tag cloud (or at least a weighted list) can be attributed to the "subconscious files" in Douglas Coupland's Microserfs (1995). In Lester Leaps Out, the Welsh poet Doug Lang uses the same logic of weighted texts to create a graphical word-map of jazz music. The poem appears in his book, Magic Fire Chevrolet(1980).

[edit] Types

There are three main types of tag cloud applications in social software, distinguished by their meaning rather than appearance. In the first type, there is a tag cloud for each item whereas in the second type, we have global tag clouds where the frequencies are aggregated over all items and users.

In the first type, size represents the number of times that tag has been applied to a single item.[4] This is useful as a means of displaying metadata about an item that has been democratically 'voted' on and where precise results are not desired. A good example of this is Last.fm, which uses this method as a means of displaying the genre with which an artist or track has been tagged.

In the second, more commonly used type, size represents the number of items to which a tag has been applied, as a presentation of each tag's popularity. Examples of this type of tag cloud are used on the image-hosting service Flickr and the blog aggregator Technorati.

In the third type, tags are used as a categorization method for content items. Tags are represented in a cloud where larger tags represent the quantity of content items in that category.

More generally, the same visual technique can be used to display non-tag data[5], as in a Data Cloud.

[edit] Visual appearance

Tags clouds are typically represented using inline HTML elements. The tags can appear in alphabetical order, in a random order, they can be sorted by weight, and so on. Some prefer to cluster the tags semantically[6][7] so that similar tags will appear near each other. Heuristics can be used to reduce the size of the tag cloud whether or not we are trying to cluster the tags.[7]

[edit] See also

[edit] References

  1. ^ Martin Halvey and Mark T. Keane, An Assessment of Tag Presentation Techniques, poster presentation at WWW 2007, 2007
  2. ^ Paul Bausch, Jim Bumgardner (2006). "Make a Flickr-Style Tag Cloud", Flickr Hacks. O'Reilly Press. ISBN 0596102453. 
  3. ^ A copy of Jim Flanagan's Search Referral Zeitgeist was available at archive.org but has since been blocked. In the comments of a blog entry, a user identified as Steve Minutillo attribute the idea to Jim Flanagan, stating that Flanagan's site had such displays in 2002.
  4. ^ Bielenberg, K. and Zacher, M., Groups in Social Software: Utilizing Tagging to Integrate Individual Contexts for Social Navigation, Masters Thesis submitted to the Program of Digital Media, Unisersitat Bremen (2006)
  5. ^ Kamel Aouiche, Daniel Lemire, Robert Godin, Collaborative OLAP with Tag Clouds: Web 2.0 OLAP Formalism and Experimental Evaluation, WEBIST 2008, 2008.
  6. ^ Hassan-Montero, Y., Herrero-Solana, V. Improving Tag-Clouds as Visual Information Retrieval Interfaces
  7. ^ a b Owen Kaser and Daniel Lemire, Tag-Cloud Drawing: Algorithms for Cloud Visualization, Tagging and Metadata for Social Information Organization (WWW 2007), 2007


[edit] External links

[edit] Tag Cloud Examples

[edit] Tag Cloud Tools and Articles

[edit] File Formats

  • APML Attention Profiling Markup Language is often used to store and import/export Tag Clouds