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December 14, 2008

What are Tag Clouds ?

Tag Clouds are a navigation tool seen increasingly on websites these days. Tag Clouds are a non-hierarchical presentation of hyperlinked key words, emphasized by frequency or importance. I'm experimenting with different types of tag clouds in the blog.

There are different ways to structure and categorize information - in books, websites, etc. The choice of a structure enables swift and predictable navigation, but it constrains choices and options - just like every map ignores some things while exaggerating others.


One type of structure is the Outline, a vertical list showing subordinate items by horizontal indentation. Another is the Menu, in which you choose a major category, then a sub-category, then a lesser category, then a micro-category, and then finally find the content that you want. These are modern constructs based on accepted norms in text-based decision making.

But now we see a new type of info-structure. Think of a gift basket of fruit and candy - you're presented with a jumble of options, you might need to rotate it to choose a treat, there's a lot of different things stuffed in there in a pile, and yet your brain is able to find the Junior Mints mini-pack without great difficulty.

A tag cloud is a gift basket. There are lots of choices available, they're presented without any categorical structure (the fruit, cookies and candy are all mixed up) and it works - the brain can work it out. Think about what your first response is when you come across a bountiful fruit basket - it's often, "wow, let's see what's in here. Hey, there's a kiwi! I love kiwis!".

There really is nothing new under the sun. Think about Early Man, in whatever epoch you place him. He's walking through the forest, and there's a lot of objects all around him - fruit, small game, a deadly snake, water. We've been scanning, interpreting, and prioritizing jumbled and non-hierarchical information for a long time. In fact, we're good at it, we're just not proficient at it these days.

And so, we've gone full circle and "invented" the tag cloud. The tag cloud is a visual presentation of word frequency. What's that mean? Words used more often are presented with larger letters, and the words used less are presented in lower letters. Wow, cool, new, web 2.0! Not really - road maps have been doing that for a long time now; big cities get big letters, medium cities get medium letters, tiny towns get tiny type. Nothing new there. Visual designers call it a weighted list. Compare Cuddy (bottom-left) with Pittsburgh. Notice how well you do that without consciously sounding out every single name.

So we get a jumble of words, and now we know that they're emphasized on frequency, or maybe sometimes on some definition of importance. But part of the web application means that the words in the tag cloud are links to content - and that opens up a new potential navigation schema.

Sometimes words that occur "close" to each other are grouped together by brightness (in a monochrome presentation) or by color. So it's not really just a cluster, there's a few dimensions to it, but I'm not sure how the non-digerati are supposed to get these notions.

Color is dangerous because the audience does not have a consistent habit of using color-coding, and there are non-trivial cultural implications with color. A wise use of color is variation of shades within a single hue.

Having given that quick-and-dirty understanding of tag clouds, let me back up and say -- No, that's not a definition of tag clouds, that's a definition of "word clouds"! No Fair! Everything we've said so far is really just about WORD CLOUDS.

So what's a tag cloud? What's a tag? A meta-tag or tag is a word that's significant to the meaning in an article. The word probably appears in the article, but it may not be in a headline or a sub-headline. So the NY Post headline may read There He Hos Again, but the tags might be "stupid, governor, Spitzer, repeat, hooker, prostitute, scandal, idiot". The notion is that the content is closely associated with the few words presented as tags.

In a legacy publishing perspective, the mighty Author owns the tags, and specifies the tags the author thinks are pertinent to the content. This is a taxonomy, a top-down structure. Very right-brain.

In a more recent development, publishers may open up the tagging system to the audience, and let the audience contribute tags to an article. This sort of a bottom-up schema is called a folksonomy, a tagging taxonomy created by the audience. The significance of this approach cannot be understated.

Folksonomy, or audience-tagging, allows the community of users to use their own terminology to make the content more findable to their peers. In this way, the users make the content more useful and more valuable, which is a key web2.0 concept.

What's next in cloud tags? The right-minders like the idea of audience-contributed tags, perhaps with benevolent moderating, but they don't like the messy mishegoss, so there's a flirtation with "tag indexes", user-defined tags presented in an alphabetic listing:

Some sites allow the user to choose between a tag cloud and a tag index:

Another new development in cloud tagging for websites is the "tag cloud page", an alternative sort of sitemap. Since the tag cloud needs a lot of real estate, the full-page application may achieve the promised benefits more than the 2-inch left margin placement.

The functional differences between a tag index and a tag cloud are differences of state and serendipity, or perhaps search-and-surf: the tag index assumes that the user has a particular word in mind, while the tag cloud permits notional and serendipitious discovery.

Having said what it is and listed the benefits, let's identify the negatives and say what it's not.

The downside of tag clouds are that they're intolerant of plural/singular changes and synonyms. They make an unwarranted positive assumption about user intent. They're good for serendipity but not effective for search. So they're not the Semantic Web. They're not Google. That's okay.

Tag clouds are not to be confused with cloud computing, which is something completely different. Cloud computing is replacing local hardware with offsite systems-as-a-service (SAAS).

URLs for Cloud Generators:

Further reading:


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