The Good & the Bad [10/2006]

Antony pointed me to this nice example found on BBC News.

So what is the message here? “Chinese and other foreigners (not being British nationals) more and more fill Brirish jails …”

Well, as we look at the percentage changes, we do not have any clue about the underlying group sizes. As whites are by far the larger group in this example, the absolute increase for whites is certainly much bigger. Any better display at hand?

So called “Skyline Plots” – as implemented in RENOIR – take the absolute size of groups into account by adjusting the bin width, such that the plot covers both aspects: absolute and relative change.

(This is certainly a different example as the one from BBC News, but without the absolute figures it is impossible to recreate the skyline plot for the prison example.)

Looking at the colors, we find the odd choice of coding an increase of prisoners in green and the decrease in red. (Does not make much sense, unless the graph comes from the company which runs the prison …)

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