Joining the Tag Team At Tagsonomy.com

July 22, 2007 03:11 PM | Posted in: Tag Clouds

I'll be writing about tagging, tag clouds, folksonomies, and related topics over at Tagsonomy.com going forward. As Christian Crumlish observed, it's been quite at Tagsonomy.com for a while, but that doesn't mean that tagging is anywhere close to being fully figured out.

To help kickstart the conversation, I've put up two posts since officially joining the Tag Team; The Tagging Hype Cycle, and Is Tagging a Disruptive Innovation?.

Comments are already flowing in - be sure to join the discussion.

local tags: folksonomy, metadata, social_media, tagclouds, tagging, tagsonomycom

Watching Ideas Bloom: Text Clouds of the Republican Debate At Democrats.org

May 4, 2007 08:07 PM | Posted in: Tag Clouds

A meme is emerging for the use text clouds as visualization for - and a source of insight into - political speeches and speakers.

Text clouds of the Republican Presidential candidates' debate appear front and center on the DNC blog democrats.org, in Tag Clouds Can Tell Us a Lot.... (sourced from media analysis firm Upstream Analysis via Pollster.com).

As you can see in the quote from the writeup below, we're quickly developing sophisticated readings of the (comparatively) simple visualization methods used to generate text clouds.

But sometimes a cloud also reflects concerns that voters share about a candidate. This is because the candidate gets asked about the issue--a lot--and then has to talk about it.

Check out the large "Pro-Life" tag in flip-flopping Romney's cloud, or the large "Think" tag in Giuliani's cloud--the candidate notorious for leaping first and thinking later.

Political interpretations aside, this is a nuanced reading of the resulting clouds: it recognizes the dynamic feedback link between intentions and responses that becomes visible in the rendered clouds. For a visualization geek, these clouds show the differing agendas of candidates and audience as they played out, a nice example of social mechanisms in action.

Note to the tool builders of the world
How about putting together a visualization toolset that shows evolving text clouds as the debate progresses? I'm imagining a timeline plus transcript plus cloud view of the accumulating text cloud for each candidate, with options for moving forward or back in the stream of words.

What could be better than watching words and ideas bloom over time, the same way we see flowers in a garden blossom, open, and close in time lapse photography. I'd like to think we can grow something poetic and beautiful, as well as useful, from the (sadly debased) soil of politicized sound bites surrounding us.

Or, with a nod to the brutal competition built into most natural systems, you may choose to watch the struggle of waterlillies for sunlight, in this clip from The Amazing Life of Plants.

local tags: 2008_election, ecosystems, flowers, information_overload, postliteracy, reading, tagclouds, textclouds, visualization

Text Clouds and Advertising: Microsoft's Community Buzz Project

April 28, 2007 02:47 PM | Posted in: Tag Clouds

Thanks to Datamining, for posting a writeup and screenshot of a prototype of Community Buzz, which features a text cloud. Community Buzz is a Microsoft Research project, and this is a perfect use of a text cloud to visualize concepts and further comprehension in a body of text.

More interesting than the text cloud is the space in the screenshot that looks like a placeholder for advertising driven by the contents of the text cloud. The annotation reads "Contextual ads based on the Buzz cloud keywords", implying an advertising based revenue mechanism driven by creation and analysis of a text cloud.

Community Buzz Screenshot

The description of Community Buzz posted on the TechFest 2007 page, includes the following, making the connection to an advertising model explicit:

Community Buzz combines text mining, social accounting (Netscan/MSR-Halo), and new visualization techniques to study and present the content of communication threads in online discussion groups. The merging of these research technologies results in a system that gives great value to community participants, enables highly directed advertising, and supplies rich metrics to product managers.

Assuming it's possible to provide highly directed advertising and rich metrics based on text clouds, I can see the benefits of for advertisers and product managers, and researchers of many kinds. Yet I'm not convinced of the benefits for community participants. Where will the text clouds come from, and how will their content reflect the needs of the community? How will social dynamics shape or affect these text clouds, to make it possible for them to leverage network effects, differential participation, and the scale benefits of connected social systems?

Text clouds - at least at this stage of development - support rapid but shallow comprehension: maybe this is perfect for advertising purposes...

Like a pile of dry bones that used to make up a skeleton, text clouds lack the specific structure and context of their source, and so cannot replace comprehension. Text clouds deconstruct the word elements that make up a body of text the same way spectrum analysis identifies the different wavelengths of light from a distant star. It's a bit like using statistical analysis to read King Lear, instead of using a variety of tools to learn more about what Lear might have to say.

A better use of text clouds, or any other type of deconstructive method (a variant of semiotics) is as a tool for enhancing comprehension. Text clouds seem to bypass distinctions between high context and low context that present barriers to understanding deep context, by focusing on the raw content of the source, on the level of it's constituent elements.

The goal of examining the fundamental or essential makeup of something we're exploring - as a way of better understanding that thing overall - is an epistemological method pursued by Plato and a host of other Western philosophers and natural scientists. We should be cautious with new tools, however, as the urge to illuminate and dissect the fundamental makeup of that which is complex and nuanced can go too far, crossing from the insightful to the sterile domain of soulless reductivism. Witness the responses of corrupt officials to Javier Bardem's character Agustín, in John Malkovich's directorial debut The Dancer Upstairs.

Agustín is a police hero who saves his country from a criminal and oppressive government, social disintegration, and guerilla takeover. He then surrenders all prospects of winning the presidency and leading his struggling nation to prosperity for the unrequited love of a woman who aided the same guerilla leader he helped capture. Agustín strikes a secret bargain to secure her freedom with the corrupt powers that be, on condition that he withdraw from public life. His choice is incomprehensible to the soulless officials in power. To these people, who buy, sell, and execute hundreds without a thought, Agustín's lover "...is just a girl - 70% water."

For reference, the overview of Community Buzz:

• Community Buzz combines analysis of the content of online discussions and social structure of the communities to identify hot topics and visualize how they evolve over time.


• Through search and Buzz cloud users can access relevant discussion threads and adverts linked to the search results and Buzz keywords.


• Visualization of keyword trends enables the users to monitor the popularity of selected topics. Mesasages can be filtered based on the 'social status' of the author in the community.

And the complete description of the demo mentioned by Datamining:

Community Buzz is a new window into online communities! Interesting and useful conversations, authors, and groups are discovered easily using this tool, jointly developed by Microsoft Research Redmond's Community Technologies group and Microsoft Research Cambridge's Integrated Systems team, with sponsorship from Live Labs. Community Buzz combines text mining, social accounting (Netscan/MSR-Halo), and new visualization techniques to study and present the content of communication threads in online discussion groups. The merging of these research technologies results in a system that gives great value to community participants, enables highly directed advertising, and supplies rich metrics to product managers.

local tags: advertising, film, information_overload, microsoft, postliteracy, reading, tagclouds, textclouds, visualization

Text Clouds of the Democratic Debate

April 28, 2007 01:36 PM | Posted in: Tag Clouds

Mark Blumenthal, of Pollster.com, recently posted a set of text clouds showing the words used by each candidate in the Democratic presidential debate Thursday night. The clouds were generated from transcripts of the debate, using Daniel Steinbock's Tag Crowd tool.

Candidates' Text Clouds

In the screenshot of Mark's posting, it's easy to see this is a great example of a collection of text clouds used for comparative visualization and interpretation. The goal is to enhance understanding of the meaning and content of the candidate's overall conversations during the debate, an idea I explored briefly last year.

Just a month ago, in a post that identified text clouds as a new and distinct tag cloud variant, I suggested:

text clouds may become a generally applied tool for managing growing information overload by using automated synthesis and summarization. In the information saturated future (or the information saturated present), text clouds are the common executive summary on steroids

Supporting the comparison and interpretation of political speeches is an inventive, timely, and resourceful application that could make text clouds a regular part of the new personal and professional toolkit for effectively handling the torrents of information overwhelming people in important situations like vetting political candidates.

I especially like the way this use of text clouds helps neatly sidestep the disheartening ubiquity of the soundbite, by aggregating, distilling, and summarizing all the things the candidates said. I suspect few - if any - of the campaigns realize the potential for text clouds, but they definitely know the detrimental power of soundbites:

"It's a mess," said an exasperated-sounding Mr. Prince, Mr. Edwards's deputy campaign manager. "Debates are important, but in these big multicandidate races they end up not being an exchange of ideas, but just an exchange of sound bites. They have become a distraction."

From Debates Losing a Bit of Luster in a Big Field

The value of a collection of soundbites over an insightful dialog is - apologies for the pun - debatable. But even if a simple exchange of soundbites is what the new shortened formats of many debates yields us, text clouds may help derive some value and insight from the results. The combined deconstructive and reconstructive approach that text clouds employ should make it possible to balance the weight of single remarks of candidates by placing them in a larger and more useful context.

History Repeats Itself
In the longer term view of the history of our responses to the problems of information overload, the appearance of text clouds may mark the emergence of a new general puprose tool for visualizing ever greater quantities of information to support some qualitatively beneficial end (like picking a good candidate for President, which we sorely need).

The underlying pattern - a consistent oscillation between managing effectively and ineffectively coping, depending on the balance between information quantity and tool quality - remains the same. Yet there is also value in knowing the cycles that shape our experience of handling the information crucial to making decisions, especially decisions as important as who leads the country.

The NY Times transcript of the debate is available here.

local tags: information_overload, postliteracy, reading, tagclouds, textclouds, visualization

Text Clouds: A New Form of Tag Cloud?

March 15, 2007 12:04 AM | Posted in: Tag Clouds

During 2006, tag clouds moved beyond their well-known role as navigation mechanisms and indicators of activity within social media experiences, emerging as a standard visualization technique for texts and textual data in general.

This use of tag clouds does not commonly involve tags, social networks, emergent architectures, folksonomies, or metadata.

"Text cloud" might be a more accurate label for these visualizations than tag cloud. In addition to recognizing fundamental differences - text clouds differ from tag clouds in composition (no tags at all) and purpose (predominantly comprehension, rather than access or navigation) - distinguishing the two types of clouds will make it much easier to assess their abilities to support user experience needs and business goals.

The emergence of this new form of text cloud looks like a good example of speciation in action (though it's too early to tell whether the end result will be cladogenesis or anagenesis).

Major and minor publications feature(d) text clouds as visualizations in 2006, both permanently and temporarily:

• The New York Times cloud of most searched items


• The Economist topics cloud


• The Vancouver Sun feature on real estate prices by neighborhood


• discussion on Read/Write Web


• even a book in progress

The Economist's Text cloud

In 2006, several free and public tools for generating text clouds locally on the desktop or via a service available through the Web were released. The increase in the number and variety of specific text cloud tools reflects embrace and enthusiasm for text clouds in communities of interest for information visualization, language processing, and semantics.

Some of the better known examples of text cloud tools include:

• Chirag Mehta's tool Tagline


• Daniel Steinbock's tool Tagcrowd


• Content Statistics by Ryan Grimm and Andrew Bruno of O'Reilly Research


• RhNav/Text Mining


• TextTagCloud


• IBM's data visualization service - Many Eyes which I saw demo'd at IDEA 2006

The Many Eyes Cloud

The text clouds created with these tools range across a wide spectrum of speeches and writing:

• U.S. presidential speeches as tag clouds


• The Seattle Post Intelligencer's analysis of speeches by Bill Gates, Steve Jobs, Michael Dell, and others, or their retrospective analysis of 30 years of Microsoft communications


• a Ph.D Thesis

Text clouds are meant to facilitate rapid understanding and comprehension of a body of words, links, phrases, etc. Any block of information composed of text is open to analysis as a text cloud, as these screen captures of text clouds for restaurant menus, ingredients, wikipedia, magazine covers, and even poems demonstrate.

Tim O'Reilly uses text clouds for a number of purposes:

We used them a bunch to analyze the topics, companies and people at the last FOO Camp, and they were the most useful of the visualizations we did. They helped us see where we were under- and over-represented in terms of companies and particular technologies we were wanting to explore. ...So they have many uses beyond just showing what we normally think of as tags.

Non-linear Access
The emergence of text clouds shows continuing exploration and refinement of cloud style displays as a new form of user interface, adapted to specific contexts. Continued refinement of text clouds in this direction may indicate an expanding role for commonly available and sophisticated text visualization tools to support specialized goals for information display and understanding.

Remember that Google is busy right now scanning thousands of books per day from several of the world's major academic libraries, as part of it's self-appointed labor of organizing the world's information. That's a lot of new text. How will people work with effectively with such an overwhelming amount of text, of so many different kinds, from so many different sources?

Consider the following, from Ulysses' Without Guilt by Stacy Schiff (in the New York Times):

Recently Cathleen Black, president of Hearst Magazines, urged a group of publishing executives to think of their audience as consumers rather than readers. She's onto something: arguably the very definition of reading has changed. So Google asserts in defending its right to scan copyrighted materials. The process of digitizing books transforms them, the company contends, into something else; our engagement with a text is different when we call it up online. We are no longer reading. We're searching - a function that conveniently did not exist when the concept of copyright was established.

On a larger scale, the growing use of text clouds hints at a (potential) deeper cultural shift in the way we go about reading and comprehension: a shift from linear modes based on reading words and sentences, to nonlinear modes based on viewing summaries of content in aggregate as a way of discovering concepts and patterns. (Finally, a legitimate use for Twitter...) Experimenting with text clouds for non-linear reading and comprehension (now that's a sexy term...) is a natural evolution of the role cloud style displays play as an alternative / compliment / supplement to the list based navigation now dominant in user experiences.

A Text Cloud of Twitter Posts (A TwitterCloud?)

I'm not predicting the end of reading as we know it, nor the end of navigation as we know it: both will be with us for a long, long time. But I do believe that text clouds might constitute an emerging method for augmenting comprehension and display of text, with broad potential uses.

Enterprising Clouds
What about someone lacking time to fully read a Shakespeare play, or a faddish business book, but who needs to understand something about that book's meaning and substance? A text cloud creation tool could extract the most commonly mentioned terms, and otherwise profile the words that make up the text. It would be risky to rely on a shallow text cloud (and Tim O'Reilly mentions this specifically) for deep comprehension, but it would be enough to understand the concepts that appear, and allow polite conversation at a networking event, or lunch with that certain manager who recommended the book.

If I were entrepreneurial, I'd source a set of free electronic versions of classic texts, process them with one of the free text cloud tools, apply some XSLT and other transformations to generate consistent readable formatting, and sell the results as a line of ebooks called "Cloud Notes". Of course, someone's beaten me to it already...

What's in store for the future?
In this fashion, text clouds may become a generally applied tool for managing growing information overload by using automated synthesis and summarization. In the information saturated future (or the information saturated present), text clouds are the common executive summary on steroids and acid simultaneously; assembled with muscular syntactical and semantic processing, and fed to reading-fatigued post-literates as swirling blobs of giant words in wild colors, it consists of signifiers for reified concepts that tweak the eye-brain-language conduit directly.

local tags: information_overload, postliteracy, reading, tagclouds, textclouds, visualization

2.3% Of Chinese Internet Users Tag, Baidu Reports

March 4, 2007 07:54 PM | Posted in: Tag Clouds

A posting from China Web2.0 Review shared results of a report on Chinese tagging rates released by Baidu, China's leading search engine.

I was not able to locate a translation of the original report from Baidu, so I'll quote the summary from China Web2.0 Review:

According to the report, only 2.3% of internet users have ever used tag, they mainly use tags in social bookmarking and blogs. I don't know the methods of data collection, but the report said about 15 million Chinese webpages were bookmarked by users, on average each user has saved 40 online bookmarks. Among them, over 90% users add less than two tags for a bookmark.
And based on the tags of user saved bookmarks, the most used tags are "software download", "BBS", "entertainment", "game" and "learning".

We don't know which services are included for analysis in the report, so I have no idea to which extent I can trust it. But based on my observation, I agree with the basic finding of the report, even though more and more services have embodied tagging feature, only a very small part of early-adopters in China indeed use it.

Two things come to mind right away:

1. The maturity, structure, and usage patterns of the Internet in China are not directly comparable to the maturity maturity, structure, and usage patterns of the Internet elsewhere (largely due to substantial restrictions and censorship by the Chinese government)
2. Official Chinse positions are not fully reliable, and so the numbers, context, and usage described could be very different from real practices

Still, even with the absence of solid qualifying, corroborating, or contextual information, this rate of adoption for tagging seems consistent with the rest of the very rapid pace of modernization in China.

And as the First Principle of Tag Clouds - "Where there's tags, there's a tag cloud" - says, this means there are quite a few tag clouds on the way in China.

local tags: baidu, china, social_bookmarking, tagclouds, tagging, web20

10 Best Practices For Displaying Tag Clouds

February 25, 2007 01:31 AM | Posted in: Tag Clouds

This is a short list of best practices for rendering and displaying tag clouds that I originally circulated on the IXDG mailing list, and am now posting in response to several requests. These best practices are not in order of priority - they're simple enumerated.

1. Use a single color for the tags in the rendered cloud: this will allow visitors to identify finer distinctions in the size differences. Employ more than one color with discretion. If using more than one color, offer the capability to switch between single color and multiple color views of the cloud.
2. Use a single sans serif font family: this will improve the overall readability of the rendered cloud.
3. If accurate comparison of relative weight (seeing the size differences amongst tags) is more important than overall readability, use a monospace font.
4. If comprehension of tags and understanding the meaning is more important, use a variably spaced font that is easy to read.
5. Use consistent and proportional spacing to separate the tags in the rendered tag cloud. Proportional means that the spacing between tags varies based on their size; typically more space is used for larger sizes. Consistent means that for each tag of a certain size, the spacing remains the same. In html, spacing is often determined by setting style parameters like padding or margins for the individual tags.
6. Avoid separator characters between tags: they can be confused for small tags.
7. Carefully consider rendering in flash, or another vector-based method, if your users will experience the cloud largely through older browsers / agents: the font rendering in older browsers is not always good or consistent, but it is important that the cloud offer text that is readily digestible by search and indexing engines, both locally and publicly
8. If rendering the cloud in html, set the font size of rendered tags using whole percentages, rather than pixel sizes or decimals: this gives the display agent more freedom to adjust its final rendering.
9. Do not insert line breaks: this allows the rendering agent to adjust the placement of line breaks to suit the rendering context.
10. Offer the ability to change the order between at least two options - alphabetical, and one variable dimension (overall weight, frequency, recency, etc.)

For fun, I've run these 10 best practices through Tagcrowd. The major concepts show up well - font, color, and size are prominent - but obviously the specifics of the things discussed remain opaque.

Best Practices For Display as a Text Cloud

local tags: tagclouds, tagging, visualization

PEW Report Shows 28% Of Internet Users Have Tagged

February 1, 2007 02:30 PM | Posted in: Tag Clouds

The Pew Internet & American Life Project just released a report on tagging that finds
28% of internet users have tagged or categorized content online such as photos, news stories or
blog posts. On a typical day online, 7% of internet users say they tag or categorize online content.

The authors note "This is the first time the Project has asked about tagging, so it is not clear exactly how fast the trend is growing."

Wow - I'd say it's growing extremely quickly. Though I am on record as a believer in the bright future of tag clouds, I admit I'm surprised by these results. The fact that 7% of internet users tag daily is what's most significant: it's an indication of very rapid adoption for the practice of tagging in many different contexts and many different kinds of audiences, given it's brief history.

I'd guess this adoption rate compares to the rates of adoption for other new network-dependent or emergent architectures like P2P music sharing or on-line music buying.

You're correct if you're thinking there is a difference between tagging and tag clouds. And if you've read the report and the accompanying interview with Dr. Weinberger, you've likely realized that neither Dr. Weinberger's interview nor the report specifically addresses tag cloud usage. But remember the First Principle of Tag Clouds: "Where there's tags, there's a tag cloud." By definition, any item with an associated collection of tags has a tag cloud, regardless of whether that tag cloud is directly visible and actionable in the user experience. So that 7% of internet users who tag daily are by default creating and working with tag clouds daily.

It might be time for tag clouds to look into getting some sunglasses.

local tags: pew, social_systems, tagclouds, tagging

Cartograms, Tag Clouds and Visualization

May 22, 2006 10:56 PM | Posted in: Ideas , Tag Clouds

I was enjoying some of the engaging cartograms available from Worldmapper, when I realized tag clouds might have some strong parallels with cartograms. After a quick substitution exercise, I've come to believe tag clouds could be to lists of metadata what cartograms are to maps; attempted solutions to similar visualization problems driven by common and historically consistent information needs.

Here's the train of thought behind the analogy. Cartograms are the distorted but captivating maps that change the familiar shapes of places on a map to visually show data about geographic locations. Cartograms change the way locations appear to make a point or communicate relative differences in the underlying data; for example, by making countries with higher GDP (gross domestic product) bigger, and those with lower GDP smaller. In the example below, Japan's size is much larger than it's geographic area, because it's GDP is so high (it's the dark green blob on the far right, much larger than China or India), while Africa is nearly invisible.

Gross Domestic Product

Tag clouds pursue the same goal: to enhance our understanding by communicating contextual meaning through changes in the way a set of things are visualized, relying additional dimensions of information to make context explicit. Where cartograms change geographic units, tag clouds change the display of a list of labels (the end point of a chain of linkages connecting concepts to focuses) to communicate the semantic importance or context of the underlying concepts shown in the list.
Visually, the relationship of clouds to lists is similar to that of maps and cartograms; compare these two renderings of the most popular search terms recorded by nytimes.com, one a simple list and the other a tag cloud.

List Rendering of Search Terms

Cloud Rendering of Search Terms

This explanation of cartograms from Cartogram Central a site supported by the U.S. Geological Survey and tional Center for Geographic Information and Analysis makes the parallels clearer, in greater detail.
"A cartogram is a type of graphic that depicts attributes of geographic objects as the object's area. Because a cartogram does not depict geographic space, but rather changes the size of objects depending on a certain attribute, a cartogram is not a true map. Cartograms vary on their degree in which geographic space is changed; some appear very similar to a map, however some look nothing like a map at all."

Now for the cut and paste. Substitute 'tag cloud' for cartogram, 'semantic' for geographic, and 'list' in for map, and the same explanation reads:

"A tag cloud is a type of graphic that depicts attributes of semantic objects as the object's area. Because a tag cloud does not depict semantic space, but rather changes the size of objects depending on a certain attribute, a tag cloud is not a true list. Tag Clouds vary on their degree in which semantic space is changed; some appear very similar to a list, however some look nothing like a list at all."

This is a good match for the current understanding of tag clouds.

Diving in deeper, Cartogram Central offers an excerpt from Cartography: Thematic Map Design, that goes into more detail about the specific characteristics of cartograms.

Erwin Raisz called cartograms 'diagrammatic maps.' Today they might be called cartograms, value-by-area maps, anamorphated images or simply spatial transformations. Whatever their name, cartograms are unique representations of geographical space. Examined more closely, the value-by-area mapping technique encodes the mapped data in a simple and efficient manner with no data generalization or loss of detail. Two forms, contiguous and non-contiguous, have become popular. Mapping requirements include the preservation of shape, orientation contiguity, and data that have suitable variation. Successful communication depends on how well the map reader recognizes the shapes of the internal enumeration units, the accuracy of estimating these areas, and effective legend design. Complex forms include the two-variable map. Cartogram construction may be by manual or computer means. In either method, a careful examination of the logic behind the use of the cartogram must first be undertaken."

Doing the same substitution exercise on this excerpt with the addition of 'relevance' for value, 'size' for area, and 'term' for shape, yields similar results:

"Erwin Raisz called tag clouds 'diagrammatic lists.' Today they might be called tag clouds, relevance-by-size lists, anamorphated images or simply spatial transformations. Whatever their name, tag clouds are unique representations of semantic space. Examined more closely, the relevance-by-size listing technique encodes the listed data in a simple and efficient manner with no data generalization or loss of detail. Two forms, contiguous and non-contiguous, have become popular. Listing requirements include the preservation of term, orientation, contiguity, and data that have suitable variation. Successful communication depends on how well the list reader recognizes the terms (of the internal enumeration units), the accuracy of estimating these sizes, and effective legend design. Complex forms include the two-variable list. Tag cloud construction may be by manual or computer means. In either method, a careful examination of the logic behind the use of the tag cloud must first be undertaken."

The correspondence here is strong as well.

Stable Need
The fact that cartograms and tag clouds show close parallels means that while the tag cloud may be a new user interface element emerging for the Web (and major desktop applications like Outlook, in the case of Taglocity), tag clouds as a type of visualization have strong precedents in other much more mature user experience contexts, such as the display of multiple dimensions of information within geographic or geospatial frames of reference. Instances of strong correspondence of problem solving approach in both mature and emerging contexts could indicate simple application of parallel framing (from the mature context to the emerging context) as an untested conditional, until the true extent of divergence separating the two contexts is understood. This is very common new media.

Instead, in the case of tag clouds, I think it points at stable needs driving structurally similar solutions to the basic problem of how to visually communicate important relationships and additional dimensions of meaning under the limitations of inherent flatness. The parallels between cartograms and tag clouds place the appearance of the tag cloud within the larger history of continuing exploration of new ways of visualizing information. In this view, tag clouds are a recent manifestation of the stable need to create strong and effective visual ways of conveying more than membership in a one-dimensional set (the list), or location and extent within a two-dimensional coordinate system (the map).

local tags: cartogram, cartography, tagclouds, tagging, visualization

Tag Clouds: "A New User Interface?"

May 3, 2006 10:58 PM | Posted in: Ideas , Tag Clouds

In Pivoting on tags to create better navigation UI Matt McAllister offers the idea that we're seeing "a new user interface evolving out of tag data," and uses Wikio as an example. For context, he places tag clouds within a continuum of the evolution of web navigation, from list views to the new tag-based navigation emerging now.

It's an insightful post, and it allows me to build on strong groundwork to talk more about why and how tag clouds differ from earlier forms of navigation, and will become [part of] a new user interface.

Matt identifies five 'leaps' in web navigation interfaces that I'll summarize:

1. List view; a list of links


2. Left-hand column; a standard location for lists of links used to navigate


3. Search boxes and results pages; making very large lists manageable


4. Tab navigation; a list of other navigation lists


5. Tag navigation; tag clouds

A Lesson in 'Listory'

As Matt mentions, all four predecessors to tag based navigation are really variations on the underlying form of the list. There's useful history in the evolution of lists as web navigation tools. Early lists used for navigation were static, chosen by a site owner, ordered, and flat: recall the lists of favorite sites that appeared at the bottom of so many early personal home pages.

These basic navigation lists evolved a variety of ordering schemes, (alphabetical, numeric), began to incorporate hierarchy (shown as sub-menus in navigation systems, or as indenting in the left-column Matt mentions), and allowed users to change their ordering, for example by sorting on a variety of fields or columns in search results.

From static lists whose contents do not change rapidly and reflect a single point of view, the lists employed for web navigation and search results then became dynamic, personalized, and reflective of multiple points of view. Amazon and other e-commerce destinations offered recently viewed items (yours or others), things most requested, sets bounded by date (published last year), sets driven by varying parameters (related articles), and lists determined by the navigation choices of others who followed similar paths.)

But they remained fundamentally lists. They itemized or enumerated choices of one kind or another, indicated implicit or explicit precedence through ordering or the absence of ordering, and were designed for linear interaction patterns: start at the beginning (or the end, if you preferred an alternative perspective - I still habitually read magazines from back to front...) and work your way through.

Tag clouds are different from lists, often by contents and presentation, and more importantly by basic assumption about the kind of interaction they encourage. On tag-based navigation Matt says, "This is a new layer that preempts the search box in a way. The visual representation of it is a tag cloud, but the interaction is more like a pivot." Matt's mention of the interaction hits on an important aspect that's key to understanding the differences between clouds and lists: clouds are not linear, and are not designed for linear consumption in the fashion of lists.

I'm not saying that no one will read clouds left to right (with Roman alphabets), or right to left if they're in Hebrew, or in any other way. I'm saying that tag clouds are not meant for 'reading' in the same way that lists are. As they're commonly visualized today, clouds support multiple entry points using visual differentiators such as color and size.

Starting in the middle of a list and wandering around just increases the amount of visual and cognitive work involved, since you need to remember where you started to complete your survey. Starting in the "middle" of a tag cloud - if there is such a location - with a brightly colored and big juicy visual morsel is *exactly* what you're supposed to do. It could save you quite a lot of time and effort, if the cloud is well designed and properly rendered.

Kunal Anand created a visualization of the intersections of his del.icio.us tags that shows the differences between a cloud and a list nicely. This is at heart a picture, and accordingly you can start looking at it anywhere / anyway you prefer.

Visualizing My Del.icio.us Tags

We all know what a list looks like...

iTunes Play Lists

What's In a Name?
Describing a tag cloud as a weighted list (I did until I'd thought about it further) misses this important qualitative difference, and reflects our early stages of understanding of tag clouds. The term "weighted list" is a list-centered view of tag clouds that comes from the preceding frame of reference. It's akin to describing a computer as an "arithmetic engine", or the printing press as "movable type".

[Aside: The label for tag clouds will probably change, as we develop concepts and language to frame new the user experiences and information environments that include clouds. For example, the language Matt uses - the word 'pivot' when he talks about the experience of navigating via the tag cloud in Wikio, not the word 'follow' which is a default for describing navigation - in the posting and his screencast reflects a possible shift in framing.]

A Camera Obscura For the Semantic Landscape
I've come to think of a tag cloud as something like the image produced by a camera obscura.

Camera Obscura

Where the camera obscura renders a real-world landscape, a tag cloud shows a semantic landscape like those created by Amber Frid-Jimenez at MIT.

Semantic Landscape

Semantic Landscape

Like a camera obscura image, a tag cloud is a filtered visualization of a multidimensional world. Unlike a camera obscura image, a tag cloud allows movement within the landscape. And unlike a list, tag clouds can and do show relationships more complex than one-dimensional linearity (experienced as precedence). This ability to show more than one dimension allows clouds to reflect the structure of the environment they visualize, as well as the contents of that environment. This frees tag clouds from the limitation of simply itemizing or enumerating the contents of a set, which is the fundamental achievement of a list.

Earlier, I shared some observations on the structural evolution - from static and flat to hierarchical and dynamic - of the lists used as web navigation mechanisms. As I've ventured elsewhere, we may see a similar evolution in tag clouds.

It is already clear that we're witnessing evolution in the presentation of tag clouds in step with their greater visualizatin capabilities. Clouds now rely on an expanding variety of visual cues to show an increasingly detailed view of the underlying semantic landscape: proximity, depth, brightness, intensity, color of item, color of field around item. I expect clouds will develop other cues to help depict the many connections (permanent or temporary) linking the labels in a tag cloud. It's possible that tag clouds will offer a user experience similar to some of the ontology management tools available now.

Is this "a new user interface"? That depends on how you define new. In Shaping Things, author and futurist Bruce Sterling suggests, "the future composts the past" - meaning that new elements are subsumed into the accumulation of layers past and present. In the context of navigation systems and tag clouds, that implies that we'll see mixtures of lists from the four previous stages of navigation interface, and clouds from the latest leap; a fusion of old and new.

Examples of this composting abound, from 30daytags.com to Wikio that Matt McAllister examined.

30DayTags.com Tag Clouds

Wikio Tag Cloud

As lists encouraged linear interactions as a result of their structure, it's possible that new user interfaces relying on tag clouds will encourage different kinds of seeking or finding behaviors within information experiences. In "The endangered joy of serendipity" William McKeen bemoans the decrease of serendipity as a result of precisely directed and targeted media, searching, and interactions. Tag clouds - by offering many connections and multiple entry paths simultaneously - may help rejuvenate serendipity in danger in a world of closely focused lists.

local tags: semantics, tagclouds, tagging, ux, visualization

Tag Clouds: Navigation For Landscapes of Meaning

March 14, 2006 04:53 PM | Posted in: Ideas , Tag Clouds

I believe the value of second generation clouds will be to offer ready navigation and access to deep, complex landscapes of meaning built up from the cumulative semantic information contained in many interconnected tag clouds. I'd like share some thoughts on this idea; I'll split the discussion into two posts, because there's a fair amount of material.

In a previous post on tag clouds, I suggested that the great value of first generation tag clouds is their ability to make concepts and metadata - semantic fields - broadly accessible and easy to understand and work with through visualization. I believe the shift in the balance of roles and value from first to second generation reflects natural growth in cloud usage and awareness, and builds on the two major trends of tag cloud evolution: enhanced visualization and functionality for working with clouds, and provision of extensive contextual information to accompany tag clouds.

Together, these two growth paths allow cloud consumers to follow the individual chains of understanding that intersect at connected clouds, and better achieve their goals within the information environment and outside. Fundamentally, I believe the key distinctions between first and second generation clouds will come from the way that clouds function simultaneously as visualizations and navigation mechanisms, and what they allow navigation of - landscapes of meaning that are rich in semantic content of high value.

For examples of both directions of tag cloud evolution coming together to support navigation of semantic landscapes, we can look at some of the new features del.icio.us has released in the past few months. I've collected three versions of the information architecture of the standard del.icio.us URL details page from the past seven months as an example of evolution happening right now.

The first version (screenshot and breakdown in Figure 1) shows the URL details page sometime before August 15th, 2005, when it appeared on Matt McAlister's blog.

Figure 1: Del.icio.us URL Page - August 2005

The layout or information architecture is fairly simple, offering a list of the common tags for the url / focus, a summary of the posting history, and a more detailed listing of the posting history that lists the dates and taggers who bookmarked the item, as well as the tags used for bookmarking. There's no cloud style visualization of the tags attached to this single focus available: at this time, del.icio.us offered a rendered tag cloud visualization at the aggregate level for the whole environment.

Environment and system designers know very well that as the scope and complexity of an environment increase - in this case, the number of taggers, focuses, and tags, plus their cumulative histories - it becomes more important for people to be explicitly aware of the context of any item in order to understand it properly. Explicit context becomes more important because they can rely less and less on implicit context or assumptions about context based on the universal aspects of the environment. This is how cloud consumers' needs for clearly visible and accessible chains of understanding drives the features and capabilities of tag clouds. Later versions of this page addresses these needs in differing ways, with differing levels of success.

Figure 2 shows a more recent version of the del.licio.us history for the Ma.gnolia.com service. This screenshot taken about ten days ago in early March, while I was working on a draft of this post.

Figure 2: Del.icio.us URL Page - Early March 2006

Key changes from the first version in August to this second version include:

1. Changing visualization of the Common Tags block to a cloud style rendering


2. Removing the individual tags chosen by each tagger from the Posting History block


3. The addition of a large and prominent block of space devoted to "User Notes"


4. Moving the Posting History block to the right column


5. Changing visualization of the Posting History block to a proto-cloud style rendering

The most important change in this second version is the removal of the individual sets of tags from the Posting History. Separating the tags applied to the focus from associaton with the individual taggers that chose them strips them of an important layer of context. Removing the necessary context for the tag cloud breaks the chain of understanding (Figure 3) linking taggers and cloud consumers, and obscures or increases the costs of the social conceptual exchange that is the basic value of del.icio.us to its many users. In this version, cloud consumers consumers reading the URL details page can only find specific taggers based on the concepts they've matched with this focus by visiting or navigating to each individual taggers' area within the larger del.icio.us environment one at a time.

Figure 3: Chain of Understanding

The switch to rendering the Common Tags block as a tag cloud is also important, as an indicator of the consistent spread of clouds to visualize semantic fields, and their growing role as navigation tools within the larger landscape.

The User Notes are a good example of an attempt to provide additional contextual information with (potentially) high value. User Notes are created by users exclusively for the purpose of providing context. The other forms of context shown in the new layout - the Posting History, Related Items - serve a contextual function, but are not created directly by users with this goal in mind. The difference between the two purposes for these items undoubtedly influences the way that people create them, and what they create: it's a question that more detailed investigations of tagging practices will surely examine.

The third version of the same URL history page, shown in Figure 4, was released very shortly after the second, proving tag cloud evolution is happening so quickly as to be difficult to track deliberately on a broad scale.

Figure 4: Del.icio.us URL Page - March 2006 #2

This version changes the content and layout of the Posting History block, restoring the combined display of individual taggers who tagged the URL, with the tags they applied to it, in the order in which they tagged the URL for the first time.

The third version makes two marked improvements over the first and second versions:

1. Presentation of the individual chains of understanding that intersect with this focus / cloud in navigable form, to increase awareness of the context for this item and allow users to retrace these paths to their origins


2. Presentation of individual taggers' flattened clouds that intersect this focus as navigation mechanisms for moving from the current focus to elsewhere within the larger landscape

These three different versions of the del.icio.us URL details page show that the amount and type of contextual information accompanying a single focus is increasing, and that the number of concrete navigable connections to the larger semantic landscape of which the focus is one element also increasing

Overall, it's clear that clouds are quickly emerging as navigation tools for complex landscapes of meaning, and that cloud context has and will continue to become more important for cloud creation and use.

And so before discussing the context necesary for clouds and the role of clouds as navigation aids in more detail, it will be helpful to get an overview of landscapes of meaning, and how they arise.

Landscapes of Meaning
A landscape of meaning is a densely interconnected, highly valuable, extensive information environment rich in semantic content that is created by communities of taggers who build connected tag clouds. In the early landscapes of meaning emerging now, a connection between clouds can be a common tag, tagger, or focus: any one of the three legs of the Tagging Triangle required for a tag cloud (more on this below). Because tag clouds visualize semantic fields, connected tag clouds visualize and offer access to connected semantic fields, serving as bridges between the individual accumulations of meaning each cloud contains.

Connecting hundreds of thousands of individually created clouds and fields, as del.icio.us has enabled social bookmarkers to do by providing necessary tools and infrastructure, creates a very large information environment whose terrain or geography is composed of semantic information. Such a semantic landscape is a landscape constructed or made up of meaning. It is an information environment that allows people to share concepts or for social purposes of all kinds, while supported with visualization, contextual information, functionality, and far-ranging navigation capabilities.

The flickr Landscape
flickr is a good example of a landscape of meaning that we can understand as a semantic landscape. In a previous post on tag clouds, I considered the flickr all time most popular tags cloud (shown in Figure 5) in light of the basic structure of clouds:

"The flickr style tag cloud is ...a visualization of many tag separate clouds aggregated together. ...the flickr tag cloud is the visualization of the cumulative semantic field accreted around many different focuses, by many people. ...the flickr tag cloud functions as a visualization of a semantic landscape built up from all associated concepts chosen from the combined perspectives of many separate taggers."

Figure 5: The flickr All Time Most Popular Tags Cloud

From our earlier look at the structure of first generation tag clouds we know a tag cloud visualizes a semantic field made up of concepts referred to by labels which are applied as tags to a focus of some sort by taggers.

Based on our understanding of the structure of a tag cloud as having a single focus, the flickr cloud shows something different because it includes many focuses. The flickr all time most popular tags cloud combines all the individual tag clouds around all the individual photos in flickr into a single visualization, as Figure 6 shows.

Figure 6: The flickr Landscape of Meaning

This means the flickr all time most popular tags cloud is in fact a visualization of the combined semantic fields behind each of those individual clouds. It's quite a bit bigger in scope than a traditional single focus cloud. Because the scope is so large, the amount of meaning it summarizes and conveys is tremendous. The all time most popular tags cloud is in fact a historic window on the current and historical state of the semantic landscape of flickr as a whole.

This is where context becomes critical to the proper understanding of a tag cloud. The cloud title "All time most popular tags" sets the context for this tag cloud, within the boundaries of the larger landscape environment defined and communicated by flickr's user epxerience. Without this title, the cloud is meaningless despite the large and complex semantic landscape - all of the information environment of flickr - it visualizes so effectively, because cloud consumers cannot retrace a complete chain of understanding to correctly identify the cloud's origin.

flickr - 1st Generation Landscape Navigation
The flickr cloud is a powerful navigation mechanism for quickly and easily moving about within the landscape of meaning built up by all those thousands and thousands of individual clouds. Still, because it is a first generation cloud, we cannot directly follow any of the many individual chains of understanding connecting this cloud's tags back to specific taggers, or the concepts they associate with specific photos or focuses. In this visualization, the group's understanding of meaning is more important than any individual's understanding. And so the flickr cloud does not yet allow us comprehensive navigation of the underlying semantic landscape illustrated in Figure 6 (chains of understanding suggested in light green). The flickr cloud also remains a first generation tag cloud because users cannot control its context.

Figure 7: A Semantic Landscape

Even so, these navigational and contextual needs will help identify the way that users rely on clouds to work in landscapes of meaning.

Growth of Landscapes
Landscapes of meaning like flickr, del.icio.us, or the burgeoning number of social semantic business ventures debuting as I write - typically grow from the bottom up, emerging as dozens or thousands of individual tag clouds created for different reasons by different taggers coincidentally or deliberately interconnect and overlap, all of this happening through a variety of social mechanisms. Taggers typically create connected or overlapping tag clouds one at a time, adding tags, focuses, and taggers (by creating new accounts) in the ad hoc fashion of open networks and architectures. But first we should look at the Tagging Triangle to understand the most basic elements of a tag cloud.

The Tagging Triangle
To make a tag cloud, you have to have three elements: a focus, a tagger, and a(t least one) tag. I call this the Tagging Triangle, illustrated in Figure 8. In the most common renderings of familiar tag clouds, one or two of these elements are often implied but not shown: yet all three are always present.

This illustration shows a cloud of labels, not tags, because a rendered cloud is really a list of labels. The labels shown in most first generation clouds are often tags, but structurally they could also be a set of names for taggers, as in the del.icio.us posting history block proto-cloud we saw above, or a set of focuses as in the 'Inverted Cloud' I suggested.

Figure 8: The Tagging Triangle

An Example Landscape
A simple example of the growth of semantic landscapes leads naturally to the discussion of specific ways that tag clouds will enable navigation within large landscapes of meaning.

Figure 9 shows the tag cloud accreted around a single focus. This cloud includes some of the tags that Tagger 1 has used in total across all the tag clouds she's created (those other clouds aren't shown). We'll assume that she's created other clouds for other focuses.

Figure 9: A Single Tag Cloud

When a second person, Tagger 2, tags that same focus (again with a subset of the total set of all his tags), and some of those tags are the same as those used for this focus by Tagger 1, their individual tag clouds for this focus (shown by the dashed line in the cumulative tag cloud) connect via the common tags, and the cumulative cloud grows. If any of the tags from their total sets are the same, but are not used for this focus, they form another connection between the two taggers. Figure 10 shows two individual clouds connected in both these ways.

Figure 10: Two Connected Clouds

When a third tagger adds a third cloud with common tags and unique tags around the same focus, the cumulative cloud grows, and the number of both kinds of connections between tags and taggers grows. Figure 11 shows three connected clouds.

Figure 11: Connected Clouds

Every tag cloud visualizes a semantic field, and so the result of this bottom up growth is a series of interlinked semantic fields centered around a common focus, as Figure 12 shows. Since semantic fields are made of concepts, linked fields result in linked concepts.

Figure 12: Connected Semantic Fields

The total number and the variety of kinds of interconnections amongst these three taggers, their tags, and a single focus is remarkable. As this simple example shows, the total number and density of connections linking even a moderate size population of taggers, tags, and focuses could quickly become very large. This increased scale drives qualitative and quantitative topology changes in the network that permit a landscape of meaning to emerge from connected semantic fields.

Landscapes And Depth
The accumulation of connections and concepts creates a landscape of meaning with real depth; but it's the depth of a landscape that drives its value. For this discussion, I'm defining depth loosely as the amount of semantic information or the density of the semantic field either across the whole landscape, or at a chosen point.

Value of course is a very subjective judgement. In participatory economies like that of del.icio.us, the value to individual users is predominantly one of loosely structured semantic exchange based on accumulation of collective value through shared individual efforts. From a business viewpoint, a group of investors and yahoo as a buyer saw considerable value in the emergent landscape and / or other kinds of assets

To make the idea of depth a bit clearer, Figure 13 illustrates two views of a semantic landscape built up by the overlap of tag clouds. The aerial view shows the contents, distribution, and overlap of a number of tag clouds around a set of focuses. The horizon view shows the depth of the semantic field for each focus, based on the amount of overlap or connection between the cloud around that focus and all the other clouds.

Figure 13: Semantic Landscape Depth Views

Of course this is only a conceptual way of showing the cumulative semantic information that makes up a landscape of meaning, so it does not address the relative value of this information. Plainly some indication of the quality of the semantic information in a landscape is critical important to measurements of both depth and value. Metrics for quality could come from a combination of assessment of the diversity and granularity of the tag population for the focus, benchmarks for the domain of the focus and taggers (healthcare industry), and an estimate on the maturity of the domain, the focus, and the tag clouds in the semantic landscape.

Looking ahead, it's likely that accepted metrics for defining and describing the depth, value, and characteristics of semantic fields and landscapes will emerge as new combinations of some of the measurements used now in the realms of cognitive linguistics, set theory, system theory, topology, information theory, and quite a few other disciplines besides.

In Part Two
The second post in this series of two will follow several of the topics introduced here to conclusion, as well as cover some new topics, including:

• How chains of understanding shape needs for cloud context and navigation paths


• How the tagging triangle will define navigation within landscapes of meaning


• The emergence of stratification in landscapes of meaning


• The idea that clouds and landscapes have a shape which conveys meaning and value


• The kinds of contextual information and controls necessary for navigation and social exchanges

Watching Navigation Follow Chains of Understanding
I'll close with a screencast put together by Jon Udell that captures a wide ranging navigation path through the del.icio.us landscape.

local tags: semantics, social_systems, tagclouds, tagging, visualization

Second Generation Tag Clouds

February 23, 2006 05:34 PM | Posted in: Ideas , Tag Clouds

Lets build on the analysis of tag clouds from Tag Clouds Evolve: Understanding Tag Clouds, and look ahead at what the near future may hold for second generation tag clouds (perhaps over the next 12 to 18 months). As you read these predictions for structural and usage changes, keep two conclusions from the previous post in mind: first, adequate context is critical to sustaining the chain of understanding necessary for successful tag clouds; second, one of the most valuable aspects of tag clouds is as visualizations of semantic fields.

Based on this understanding, expect to see two broad trends second in generation tag clouds.
In the first instance, tag clouds will continue to become recognizable and comprehensible to a greater share of users as they move down the novelty curve from nouveau to known. In step with this growing awareness and familiarity, tag cloud usage will become:

1. More frequent
2. More common
3. More specialized
4. More sophisticated

In the second instance, tag cloud structures and interactions will become more complex. Expect to see:

1. More support for cloud consumers to meet their needs for context
2. Refined presentation of the semantic fields underlying clouds
3. Attached controls or features and functionality that allow cloud consumers to directly change the context, content, and presentation of clouds

Together, these broad trends mean we can expect to see a second generation of numerous and diverse tag clouds valued for content and capability over form. Second generation clouds will be easier to understand (when designed correctly...) and open to manipulation by users via increased functionality. In this way, clouds will visualize semantic fields for a greater range of situations and needs, across a greater range of specificity, in a greater diversity of information environments, for a greater number of more varied cloud consumers.

Usage Trends

To date, tag clouds have been applied to just a few kinds of focuses (links, photos, albums, blog posts are the more recognizable). In the future, expect to see specialized tag cloud implementations emerge for a tremendous variety of semantic fields and focuses: celebrities, cars, properties or homes for sale, hotels and travel destinations, products, sports teams, media of all types, political campaigns, financial markets, brands, etc.

From a business viewpoint, these tag cloud implementations will aim to advance business ventures exploring the potential value of aggregating and exposing semantic fields for a variety of strategic purposes:

1. Creating new markets
2. Understanding or changing existing markets
3. Providing value-added services
4. Establishing communities of interest / need / activity
5. Aiding oversight and regulatory imperatives for transparency and accountability.

Measurement and Insight

I think tag clouds will continue to develop as an important potential measurement and assessment vehicle for a wide variety of purposes; cloudalicious is a good example of an early use of tag clouds for insight. Other applications could include using tag clouds to present metadata in geospatial or spatiosemantic settings that combine GPS / GIS and RDF concept / knowledge structures.

Within the realm of user experience, expect to see new user research and customer insight techniques emerge that employ tag clouds as visualizations and instantiations of semantic fields. Maybe even cloud sorting?

Clouds As Navigation

Turning from the strategic to the tactical realm of experience design and information architecture, I expect tag clouds to play a growing role in the navigation of information environments as they become more common. Navigational applications comprise one of the first areas of tag cloud application. Though navigation represents a fairly narrow usage of tag clouds, in light of their considerable potential in reifying semantic fields to render them actionable, I expect navigational settings will continue to serve as a primary experimental and evolutionary venue for learning how clouds can enhance larger goals for information environments such as enhanced findability.

For new information environments, the rules for tag clouds as navigation components are largely unwritten. But many information environments already have mature navigation systems. In these settings, tag clouds will be one new type of navigation mechanism that information architects and user experience designers integrate with existing navigation mechanisms. David Fiorito's and Richard Dalton's presentation Creating a Consistent Enterprise Web Navigation Solution is a good framework / introduction for questions about how tag clouds might integrate into mature or existing navigation systems. Within their matrix of structural, associative and utility navigation modes that are invoked at varying levels of proximity to content, tag clouds have obvious strengths in the associative mode, at all levels of proximity to content, and potential strength in the structural mode. Figure 1 shows two tag clouds playing associative roles in a simple hypothetical navigation system.

Figure 1: Associative Clouds

I also expect navigation systems will feature multiple instances of different types of tag clouds. Navigation systems employing multiple clouds will use combinations of clouds from varying contexts (as flickr and technorati already do) or domains within a larger information environment to support a wide variety of purposes, including implicit and explicit comparison, or views of the environment at multiple levels of granularity or resolution (high level / low level). Figure 2 illustrates multiple clouds, Figure 3 shows clouds used to compare the semantic fields of a one focus chosen from a list, and Figure 4 shows a hierarchical layout of navigational tag clouds.

Figure 2: Multiple Clouds

Figure 3: Cloud Comparison Layout

Figure 4: Primary / Secondary Layout