Question: What do Pride and Prejudice, Swinburne’s poetry, and Green Eggs and Ham have in common?
Answer: Users of Many Eyes have uploaded word frequency data for each one.
One goal for Many Eyes was to find out just what kinds of data people wanted to visualize. In the past few weeks we’ve noticed a strong, unexpected trend: our users are extremely interested in looking at “unstructured” data sets, from Victorian poetry to the silliest Seuss, from a Ph.D dissertation to tags on del.icio.us. In response to this demand we’re happy to announce a new technique: an interactive tag cloud.
A tag cloud is a collection of words where the font size for each word corresponds to a numeric value, such as frequency. These purely verbal pictures are at least a decade old but have become something of a Web 2.0 emblem, visualizing the descriptive “tags” users attach to objects. Our tag cloud–created by ace intern Guilherme Boettcher–follows the standard model but adds a couple of features that make it more than an emblem.
You can do an instant, interactive search to narrow down the set of terms. As with all our visualizations, you can highlight sets of items to point out discoveries to other people. You can use a tag cloud on tabular data (a column of words and a column of numbers) but we’ve also revamped our data model to allow you to upload freeform text. That means we can do word frequency calculations for you, including removing common words across several languages and an option for finding two-word phrases. We also can show you the context of any word or phrase when you point to it with your mouse.
This technique still qualifies as experimental—and we encourage you to experiment! One excellent source of public domain books is Project Gutenberg. We’re curious to see what you come up with. (You can read this introduction for detailed instructions as well as a discussion of some of the pluses and minuses of the cloud technique.) And now that Many Eyes allows you to upload freeform text, look for more “unstructured” visualizations in the future.
March 8th, 2007 at 10:30 am
This is an interesting feature, especially because it is so widely used now and so familiar to people.
I especially like the “Expert Notes” at the bottom of the Tag Cloud Guide cautioning against the overemphasis of longer words. These “finer points” are often ignored when people use visualization, yet they make all the difference when using the methods for actual work.
Which brings me to a question: do you scale the type by the number being represented, or by its square root? Double the value and thus double the type size will lead to four times the area covered by the same word. I am not sure about perception of type, but I would guess that we mostly look at the area, hence also the problem with long words.
March 8th, 2007 at 11:11 am
Hi Robert! Like you, our intuition was that area was the key visual variable, so we scale by the square root. I don’t know any studies that test this intuition–any blog readers have references?
March 8th, 2007 at 4:06 pm
Excellent! As for studies: I don’t know of any, but this seems like a worthwhile topic to look into. In addition to the things you mention on the Tag Cloud Guide page, I would think that people can only pick out the largest words, but not estimate the differences very precisely. In that sense, a list might even be more useful than a tag cloud. But the cloud certainly looks cooler …
August 31st, 2007 at 12:26 pm
[…] One of the most popular visualizations on Many Eyes is the tag cloud. It’s easy to see the appeal: a tag cloud gives a quick, strong sense of the gist of a text. A good example is the image below, which shows Martin Luther King’s famous “I have a dream” speech. […]