The editor of "Simple Complexity" found at http://simplecomplexity.net/ came up with a very strong argument as to why pie charts are not always the best way to go when trying to put across numbers, and are actually quite misleading at times due to the fact that our poor little brains aren't all that good at judging the areas of the various segments.
It's not all that easy is it? Now check out the dot chart below and try and do the same ranking exercise.Which is easier to understand? the vast majority of people will find making sense of the numbers involved in the dot chart. Both charts show the same numbers and are as follows A = 25, C = 21, D = 18, E = 10, F = 10.