"Data visualization is the use of tools to represent data in the form of charts, maps, tag clouds, animations, or any graphical means that make content easier to understand. Graphic representations of data are popular because they open up the way we think about data, reveal hidden patterns, and highlight connections among elements. Because current web applications allow anyone with access to data to enter information and easily create a virtualization of it, students, informal learners, and the purely curious can now easily create visualizations that might reveal trends that were not obvious from the numbers alone. For scholars, particularly those whose conclusions depend on interpretation of complex statistics, data visualization offers the promise of easier communication and a wider audience for their findings."
--From the abstract to the Educause document, 7 Things You Should Know About Data Visualization II
Here's a quick search of relevant material held at QUT Library - Data Visualization