The Shortcomings of Data Visualisation

The problem with pie charts and how this relates to data visualisation as a whole.

Many visualization types have cropped up just in the past two decades, riding the growth of the internet. But they nevertheless share many characteristics with the garden-variety pie chart, including some of its primary weaknesses and a slew of new ones. Recognizing them will move science closer to tools that work for users, rather than the other way around. […]

Unfortunately, the pie chart incorporates tasks that we humans systematically fail to perform accurately, all those exercises that come at the bottom of the hierarchy of perceptual tasks […]. So although we’re good at comparing linear distances along a scale — judging which of two lines is longer, a task used in bar graphs — and we’re even better at judging the position of points along a scale, pie charts don’t bring those skills to bear. They do ask us compare angles, but we tend to underestimate acute angles, overestimate obtuse angles, and take horizontally bisected angles as much larger than their vertical counterparts. The problems worsen when we’re asked to judge area and volume: Regular as clockwork, we overestimate the size of smaller objects and underestimate the size of larger ones, to a much greater degree with volume than with area.

Newer visualizations can have these defects and more.

via Link Banana