Visualizing with Clarity - Data Points: Visualization That Means Something - page 544

During the exploration phase, you get to look at your data from a variety of
angles and browse various facets, without having to dwell on charting stan-
dards and clarity. You understand a chart better because you know more about
the data after you examine lots of other quickly generated charts. However,
when you use graphics to present results to other people, you must make
your graphics readable to those who don't know your data as well as you do.
A common mistake is that all visualization must be simple , but this skips a
step. You should actually design graphics that lend clarity, and that clarity
can make a chart “simple” to read. However, sometimes a dataset is complex,
so the visualization must be complex. The visualization might still work if it
provides useful insights that you wouldn't get from a spreadsheet.
As an effort toward clarity, people often preach removing all elements of a
graphic that don't help you interpret the data. When you “let the data speak,”
you have done your job. This is fine, but it assumes the only goal of visual-
ization is quick analytical insight, which is a small subset of what you can get
out of data. It's okay to ponder and reflect, and elements that are not helpful
in one situation might be helpful in another.
That said, whether it's a custom analysis tool or data art, make graphics to
help others understand the data that you've abstracted, and try your best not
to confuse your audience. How do you do this? Learn how we see data, and
use that to your advantage.
VISUAL HIERARCHY
When you look at visualization for the first time, your eyes dart around trying
to find a point of interest. Actually, when you look at anything, you tend to
spot things that stand out, such as bright colors, shapes that are bigger than
the rest, or people who are on the long tail of the height curve. Orange cones
and yellow signs are used to alert you on the highway of an accident or con-
struction because they stand out from the monotony of the black pavement.
In contrast, Waldo is hard to find right away because he doesn't stand out
enough to stick out in a sea of people.
You can use this to your advantage as you visualize data. Highlight data with
bolder colors than the other visual elements, and lighten or soften other ele-
ments so they sit in the background. Use arrows and lines to direct eyes to the