Understanding Data - Data Points: Visualization That Means Something - page 2

When you ask people what data is, most reply with a vague description of
something that resembles a spreadsheet or a bucket of numbers. The more
technically savvy might mention databases or warehouses. However, this is
just the format that the data comes in and how it is stored, and it doesn't say
anything about what data is or what any particular dataset represents. It's an
easy trap to fall in because when you ask for data, you usually get a computer
file, and it's hard to think of computer output as anything but just that. Look
beyond the file though, and you get something more meaningful.
W HAT DATA R E PR ES E N T S
Data is more than numbers, and to visualize it, you must know what it rep-
resents. Data represents real life. It's a snapshot of the world in the same way
that a photograph captures a small moment in time.
Look at Figure 1-1. If you were to come across this photo, isolated from every-
thing else, and I told you nothing about it, you wouldn't get much out of it. It's
just another wedding photo. For me though, it's a happy moment during one
of the best days of my life. That's my wife on the left, all dolled up, and me on
the right, wearing something other than jeans and a T-shirt for a change. The
FIGUR E 1-1 A single photo, a
single data point