Engaging viewers with interesting depictions of data always bears the risk of creating misleading or unreadable graphics. The square pie chart (or waffle chart) strikes a good balance between being interesting and not distorting the data. Here is an argument for the power of the pie and against the boredom of the bar.

When Al Gore talks about global warming, Hans Rosling shows the relationship between health and wealth, and the New York Times visualizes primary results and American consumer debt, they communicate visually. But they only use visual representation to get their point across, as a means to an end. When we want to show why visualization is effective, we have to care about the message, too – not just the method.

While reading Jarke van Wijk's Views on Visualization^(ref), I could not help but notice the negative references he makes to the subjectivity of visualization. A visualization science on par with statistics would certainly require the elimination of any and all subjectivity. I do not think that visualization is such a science, or that it being that is even all that desirable.

I used the Presidential Demographics chart in my talk at the Impact of Social Data Visualization panel at InfoVis 2007, and got some interesting responses to that. There is some interest in printing this out, so I have made a new version of the chart that is now also available as a PDF. Stephen Few used Joseph Berk's term "interocular traumatic impact" – a visualization that hits you between the eyes – to describe it. And this is exactly what visualization can do extremely effectively: visual communication, and not just of data.

The recipients of the Nobel Peace Prize 2007 are Al Gore and the UN Intergovernmental Panel on Climate Change. While the decision is undoubtedly a political one (not unlike this year's Nobel Literature Prize), Gore has made a huge impact with his documentary, An Inconvenient Truth. A large part of that comes from his use of graphs and charts.

Enormous amounts of information are technically freely available, but are hard to access in practice. A lot of that data comes from data collection funded by taxpayers, or from data that needs to be reported for legal reasons. While much of that data has been lying around on the Internet for some time, only recently have people started building tools that make it easy (and often even fun) to play with it. Even though the types of data are very different, all these tools have one thing in common: they are primarily visual.