Finalizing your visual
On top of the specific guidelines to follow for each type of chart, which we have encountered in the previous pages, there are some general quality design rules that apply every time. The common denominator of such rules brings us back to where we started at the beginning of the chapter: minimalism is the ultimate key to effective data visualization.
Yale University professor Edward Tufte has been a pioneer in modern data visualization. One of the key concepts he introduced is the data-ink ratio, which describes the prevalence of data-driven visual elements in a chart. Consider all the "ink" you use in a chart to draw the essential, non-redundant display of data information: if we erased these chart elements, we would also remove the underlying business message we wanted to convey. Now think about the total ink you would need to print the chart, which includes non-required legends, background pictures, unneeded text, and so on. Tufte found out that...
