"The greatest value of a picture is when it forces us to notice what we never expected to see." - John W. Tukey

Using data viz helps you take advantage of the brain’s ability to efficiently process visuals. You may be able to learn something about the data that could not be easily understood by reading the raw data.

Choosing the right type of visualization depends on what you need to show. Consider:

What question are you trying to answer?
What comparison, distribution, composition, or relationship are you trying to show?
How much detail does the audience need to fully understand the data?

There are two goals for data visualization: Exploration and Explanation

Exploration helps you learn more about your data.

What is the data telling you?
Identify patterns or exceptions to a pattern
Help you better understand and make sense of the data
See what would be difficult or impossible to see if presented in a different way
Find new relationships

Explanation helps tell a story to your audience.

Show a comparison or contrast in the data
Explain, make a point, or help someone decide
Improve or aid communication
Present more clearly or more forcefully than would be accomplished with text
Visually support a report, add interest to dashboards or infographics

Anscombe's Quartet shows how visualization is important and valuable for understanding and interpreting data. Watch the video to see an explanation of how four different data sets all with the exact same summary stats can be very different when turned into a visualization.