Visualizing with Clarity - Data Points: Visualization That Means Something - page 561

It's easy to see how this works in practice. Decrease the space between the
labels and small charts (refer to Figure 5-15), and you get Figure 5-19. Although
you can figure out which bars correspond to which labels by their positions,
it is not immediately clear.
The same applies even if you don't want to show specific groups. Figure 5-20
is the map from Chapter 1, “Understanding Data,” which shows fatal crashes
in the United States. The top version uses small dots to show each accident,
and the bottom version uses larger circles.
Because small dots are used in the top version, it's easier to see the pattern
of roads and city centers. The negative space in between points help show
where there are no roads or where fewer people drive cars. Places where there
is no data is just as important as the places where there is data. On the other
hand, the bottom version uses large circles that are relatively large compared
to the size of the United States and the total number of crashes during the
selected time period. There is practically no negative space, so roads and city
centers are hidden by the data, and you only see country boundaries. Without
a sufficient amount of negative space, the visualization is useless.
FIGU R E 5-19 Decreased negative
space, decreased readability