Once again we found a chart worth mentioning here. It shows the self-assessment of women in different age groups regarding their risk of a heart disease according to a current study. At first sight we actually saw only a number of seemingly random columns. So we thought about a clearer representation.
In the first chart using clustered bars it is the viewer’s job to summarize and contrast the figures of the age groups. A stacked column chart seems to be better suited to convey the statistics. Apparently, older women have a far more negative view about their risk of a heart disease (a more realistic one according to the story). Visually adding up “high” and “medium” values by stacking and displaying connector lines seem to help a lot to understand the data.