A Visualisation Is A Translation
A visualisation is a translation - from the language of numbers, which humans read slowly and badly, into the language of visual perception, which humans read instantly. Like any translation it can be faithful or it can lie, and the difference is a matter of craft, not taste. The human eye judges some things fairly accurately, such as relative positions along a scale, and other things poorly, like the precise intensity of a colour or angle in a pie chart. A good visualisation encodes the most important quantity in the most accurately read channel; a careless one buries the key number in the channel the eye reads worst. We know which is which, and we know the distortions that mislead even when no one intends them to, such as axes that exaggerate a trivial change by starting far from zero. A visualisation that misleads is worse than none at all, because it can lead to confident decisions on false premises.