Understanding Data - Data Points: Visualization That Means Something - page 30

FIGURE 1-21 Accident distributions over time

UNCERTAINTY

A lot of data is estimates rather than absolute counts. An analyst considers
the evidence (such as a sample), and makes an education guess about a full
population. That educated guess has uncertainty attached to it. You do this
all the time in your day-to-day. You make a guess based on what you know,
read, or what someone told you, and you can say with some (possibly rough)
certainty that you're right. Are you absolutely positive or are you basically
clueless? It works the same with data.

Note: It's tempting to look at data as absolute
truth, because we associate numbers with fact,
but more often than not, data is an educated
guess. Your goal is to use data that doesn't have
large levels of uncertainty attached.

When I was a young lad, a recent engineering graduate
with a statistics minor, I had a 9-month gap in between
college and graduate school. I took a few temporary jobs
that paid a little more than minimum wage, and they were
mind-numbingly boring, so naturally my mind wandered
to more engaging things.