Simple charts (pie charts, bar charts, stacked bar charts, etc) are commonly used to represent data, partially because they are easy to construct and are routinely provided by software packages. However, instead of helping comprehension, they can be surprisingly difficult to interpret, especially when many values had to be compared. The purpose of this project was to investigate this problem by designing a trial program that added interactive aspects into stacked bar charts and measured user responses. The results from these trials show that interactivity helped users understand the data and...