Tag cloud

An early printed example of a weighted list of English keywords was the "subconscious files" in Douglas Coupland's Microserfs (1995).

[4] The specific visual form and common use of the term "tag cloud" rose to prominence in the first decade of the 21st century as a widespread feature of early Web 2.0 websites and blogs, used primarily to visualize the frequency distribution of keyword metadata that describe website content, and as a navigation aid.

Oversaturation of the tag cloud method and ambivalence about its utility as a web-navigation tool led to a decline of usage among these early adopters.

[6] Flickr gave a five-word acceptance speech for the 2006 "Best Practices" Webby Award, which simply stated "sorry about the tag clouds.

"[7] A second generation of software development discovered a wider diversity of uses for tag clouds as a basic visualization method for text data.

There are three main types of tag cloud applications in social software, distinguished by their meaning rather than appearance.

In the first type, size represents the number of times that tag has been applied to a single item.

[8] 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.

In recent years tag clouds have gained popularity because of their role in search engine optimization of Web pages as well as supporting the user in navigating the content in an information system efficiently.

Tags clouds to be used on the web must be in HTML, not graphics, to make them robot-readable, they must be constructed on the client side using the fonts available in the browser, and they must fit in a rectangular box.

[20] It is similar to a tag cloud[21] but instead of word count, displays data such as population or stock market prices.

The following summary is based on an overview of research results given by Lohmann et al.:[15] Felix et al.[26] compared how human reading performance differs from traditional tag clouds that map numeric values to the size of the font and alternative designs that uses for example color or additional shapes like circle and bars.

Since the number of indexed items per descriptor is usually distributed according to a power law,[28] for larger ranges of values, a logarithmic representation makes sense.

There are also websites creating artificially or randomly weighted tag clouds, for advertising, or for humorous results.