Misleading charts
Fancy, but quite misleading graphs. Can you actually see that “A” and “G” are the same? Which one do you think is the largest number? Would you say that “D” is greater than “C”? They call it the funnel chart.

Ok, now the same data represented by its first cousin, the pyramid chart.

Can you actually believe this is the same data set? Who came up with this nonsense?
Here are the actual numbers and the plain bar chart.

| Label | Value |
|---|---|
| A | 600 |
| B | 800 |
| C | 850 |
| D | 875 |
| E | 760 |
| F | 598 |
| G | 600 |
Something to think about. Moral of the story: beware the fancy graphs, especially when dealing with finances. Apparently the funnel and pyramid charts are frequently used in sales projections and similar. My suggestion, use the bar chart or pie chart instead.
And finally, a good reference on charts; The Visual Display of Quantitative Information by Edward R. Tufte. Among good practices you will also find sections on graphical integrity, distortion in data graphics, lie factor, and the data-ink ratio.
Bad Graphics - Funnel Chart » PTS Blog:
[...] Misleading charts, Damir Sudarevic of Damir Systems describes the problems with the funnel and pyramid charts offered [...]
2008-06-30, 03:28 UTC