Thursday, February 7, 2013

Extracting the Epidemic Model: Going Beyond Florence Nightingale Part II

This is the second of a two part reexamination of Florence Nightingale's data visualization based on her innovative cam diagrams (my term) shown in Figure 1.

Figure 1. Nightingale's original cam diagrams (click to enlarge)


In Part I, I showed that FN applied sectoral areas, rather than a pie chart or conventional histogram, to reduce the visual impact of highly variable zymotic disease data from the Crimean War. She wanted to demonstrate that diminishing disease was due mostly to her sanitation methodologies. The square-root attenuation of magnitudes, arising from the use of sectoral areas, helped her accomplish that objective. In addition, I showed that a plausibly simpler visualizaiton could have been had with a single 24-month cam diagram. See Fig. 2.

Figure 2. Combined 24-month cam diagram