I've always thought that the rose diagram is an interesting example for discussing the purpose of visualisations. The positive result of this work is undeniable

I've always thought that the rose diagram is an interesting example for discussing the purpose of visualisations. The positive result of this work is undeniable, but is it a good visualisation? That depends on whether you believe the goal of a visualisation is to convince people of something, or if you believe the goal is to accurately communicate information. It excelled in the former, but failed in the latter. Quantity of deaths in the diagram is represented as the distance from the edge of the wedge to the centre of the circle. Because of this, larger quantities have proportionally much larger areas displayed, which the brain interprets as a measure of quantity. The other way this diagram is designed to convince people at the expense of accuracy is the placement of preventable deaths furthest from the centre, meaning those wedges are much larger in area for the same quantity as the inner ones, further distorting the reality. We've all seen bad representations of data by the media, politicians, and businesses criticised, but this work often seems to get a pass because of its undeniably positive outcome