3 ms·

I have no problem with pie charts. The area chart on the other hand are pure evil. For example here, how is the percentage of ios over time? Has market share g

I have no problem with pie charts. The area chart on the other hand are pure evil. For example here, how is the percentage of ios over time? Has market share grown or shrunk from Q3'11 to Q1'14? It's extremly hard to answer this kind of question except for the lucky ones getting the top or bottom slot. http://static1.businessinsider.com/image/537b72f169bedd1e04384fab-1200-924/smartphoneosmarketshare.png http://static1.businessinsider.com/image/537b72f169bedd1e043...

jameshart 11y ago
Area charts are valid only if the area is meaningful. There certainly are cases where it can make sense to use a visualization based on filled, stacked areas. Look at, for example, Weatherspark.com's colortemp visualization for historical weather trends, which shows 'percentage of time when temperature is in a particular band' over a time axis. That's a good visualization, because the quantity makes physical sense - integrating 'time in band per day' over 'days' gives you overall 'time in band'. Integrating 'market share' over 'months' gives you 'market share months', which is a meaningless value.
TazeTSchnitzel 11y ago
The big, big problem with such charts is that the vertical thickness perpendicular to the x axis of the line is the actual proportion, but your brain will look at the thickness perpendicular to the gradient. To put it visually: http://i.imgur.com/vZ7uTu1.png http://i.imgur.com/vZ7uTu1.png The pink bars are the percentage market share as your brain reads it. The green bars are the percentage market share the graph is supposed to show. (The burning sensation in your eyes is because I made a poor choice of colours.) If you were to naively look at the thickness of the black area (shown with the pink bars), it'd look like it was constant. But look at the vertical height (green bars): whatever this proportion is, the black has started small, grown massively, then contracted.

jameshart 11y ago

Area charts are valid only if the area is meaningful. There certainly are cases where it can make sense to use a visualization based on filled, stacked areas. Look at, for example, Weatherspark.com's colortemp visualization for historical weather trends, which shows 'percentage of time when temperature is in a particular band' over a time axis. That's a good visualization, because the quantity makes physical sense - integrating 'time in band per day' over 'days' gives you overall 'time in band'. Integrating 'market share' over 'months' gives you 'market share months', which is a meaningless value.

TazeTSchnitzel 11y ago

The big, big problem with such charts is that the vertical thickness perpendicular to the x axis of the line is the actual proportion, but your brain will look at the thickness perpendicular to the gradient. To put it visually: http://i.imgur.com/vZ7uTu1.png http://i.imgur.com/vZ7uTu1.png The pink bars are the percentage market share as your brain reads it. The green bars are the percentage market share the graph is supposed to show. (The burning sensation in your eyes is because I made a poor choice of colours.) If you were to naively look at the thickness of the black area (shown with the pink bars), it'd look like it was constant. But look at the vertical height (green bars): whatever this proportion is, the black has started small, grown massively, then contracted.