One of the joys of data analysis is the “aha” feeling when you figure out how different variables interact. Many of the visualizations on Many Eyes are good for inspecting the relationship between numerical variables–but until now there’s been a hole. How do you understand the relation between categories, things like political affiliations or occupations?

To fill this hole, the Matrix Chart was created by our talented intern Lee Byron. (You may already be familiar with his visualizations of music listening on last.fm.) This visualization, shown below, is a flexible and powerful way to make multivariate comparisons. It’s good for data with several non-numeric columns. For example, the matrix chart below shows data on members of the 17th Canadian Parliament, broken down by political party (y axis) and former occupation (x axis).

Here’s a second example, a visualization of NBA jersey colors. Not the most serious visualization on the site, but it does show off color customization, a first for a Many Eyes graphic.

You can read more about the technique here, and we’re collecting examples in a special topic hub, where we’ve put matrix visualizations of some existing data from the site. (One of the nice things about adding a new visualization is that it lets us revisit older data sets with a fresh pair of eyes.) You can leave comments or ideas for new features in the discussion area of the topic hub.

One last note for the technologists in the audience. This is our first experiment with Adobe Flash. We’re interested in your feedback on this as well–we’ll probably be conducting more experiments in the future.